Monthly snail-mail subscription for girls ages 9–16
Big Sister Letters is a thoughtful monthly physical letter mailed to your girl from the perspective of a "Big Sis". Each letter is written for her age and stage, addressed to her name, and paired with a companion guide for the grown-up who loves her most. No app. No feed. Designed to be a safe, encouraging space to build her confidence and nurture a resilient mind in a digital world.
Because she deserves a voice that speaks life into her, far away from the noise of the screen.
Group chats, comparison, pressure, and constant scrolling do not leave much room for a girl to hear her own thoughts. Even when nothing is wrong, the noise is still there.
Once a month, she receives a real envelope with a thoughtful letter written for her age and stage. In a time where most interactions happen behind a screen, she needs something tangible to hold onto. Something that reminds her she is capable, worthy, and deeply loved. We designed this experience to give you a meaningful way to foster her confidence.
Empowering girls with the tea, the tools, and the team they need to navigate puberty with confidence. We deliver expert information and tactical support through a sisterhood that affirms her identity and protects her peace.
Real, expert-led information delivered through the intentional, aesthetic magic of snail mail.
To remove the fear, shame, and fever dream confusion of growing up. We replace clueless panic with main character blueprints.
Through affirming letters and tactical artifacts that strengthen her internal aura and her connection to her Safe Base, her parents and mentors.
A confident, self-advocating young woman who knows her body is not a project to be fixed, but an icon in the making.
The educator and mom behind Big Sister Letters.
Big Sister Letters was founded by Genevieve Monacelli, a New York State certified Health and Physical Education teacher, certified yoga instructor, mother of four, and longtime middle school health educator. With a bachelor’s degree in Exercise Science, a master’s degree in Education, and 10 years of experience teaching middle school health, she has spent much of her career helping girls navigate puberty, reproductive health, body literacy, and the social-emotional changes that come with growing up.
What Genevieve loves most about teaching is helping girls understand their bodies without shame and giving them the kind of honest, age-appropriate guidance that builds confidence instead of confusion. Big Sister Letters grew out of that calling — a way to extend her reach beyond the classroom, support more girls in a meaningful way, and create more space to be home with her own family too.
At the heart of it all is a simple belief: knowledge is power, and girls deserve to grow up informed, confident, and proud of who they are becoming — fully aware of the power of being a woman.
We do the writing, addressing, and mailing. You do the part nobody else can — being the grown-up who supports her when her letter arrives.
Pick Pre-Teen or Teen subscription, use your email to create an account to get the monthly preview email, and enter her name and address in the shipping info to where her letter should be sent. Two minutes, no app to download.
Before her physical letter arrives, your email gets the grown-up's companion: the theme of her letter, gentle conversation guidance, and how to support her.
Letters are sent out during the first week of every month. Allow 3-7 days for the letter to land in the mailbox.
In a world of fleeting digital messages, there is something deeply exciting about receiving a physical letter. Each month, your girl receives a beautifully prepared envelope with encouragement she can hold onto.
Each month, she receives a thoughtful "big sister" letter created specifically for her age group — designed to help her feel seen, supported, and safe.
Each letter includes a small topic-related gift or keepsake that adds beauty, comfort, and a little extra meaning to the experience.
Inside each envelope, she receives thoughtful, expert-backed education and encouragement to help her navigate her health, body, friendships, confidence, identity, emotions, and growing up in today's world.
Same monthly ritual, same $15. We just choose every word — and every keepsake — for the version of her she’s being this year.
For the in-between years — when everything is starting to feel bigger.
One envelope. Cancel any month, no questions.
For the years she needs an older sister most — even if she won’t say so.
One envelope. Cancel any month, no questions.
Not sure which one fits her? Start with the closer age — you can switch any time, free.
Her letters are written for her, but you are never left guessing. Each month, before her letter arrives, you receive a private companion email so you know what encouragement she is receiving and how to support her well. So when she finally talks, you’re ready.
Before her physical envelope arrives in the mail, you receive a private email with the month's theme, a preview of her letter, and simple context on why this topic matters right now.
We know how hard it can be to get more than a one-word answer. That is why every guardian email includes a gentle, age-appropriate game plan to help you support her naturally.
Sometimes the most powerful guidance is not a perfect conversation — it is the example you live beside her every day. We help you notice the messages she may be absorbing and offer simple ways to model steadiness, respect, and self-trust in everyday moments.
In April we wrote to her about quiet courage — the kind that doesn’t make a sound. Below, three prompts to keep in your back pocket.
What is something brave you did this week that nobody noticed?
Is there a person you’d like to be braver with?
What does brave feel like in your chest?
Big Sister Letters sparked curiosity in my daughter around a topic I had tried to talk about through different books, but sometimes felt awkward bringing up. From the very first letter — and the anticipation of the next — she started learning about changes in her body and felt confident enough to begin the conversation with me herself. I highly recommend it because it takes some of the pressure off you as a parent and makes puberty feel like a more natural, even fun, conversation. I also love that the program includes a guardian email explaining what to expect each month.
I'm a member of a club?!
Anything we missed? Write to us at hello@bigsisterletters.com. A real person answers.
Our Pre-Teen subscription is generally designed for girls ages 9–12, with themes around body changes, growing confidence, friendships, and early transitions. Our Teen subscription is designed for ages 13–16 and covers deeper topics like identity, peer pressure, puberty, self-worth, boundaries, and becoming more of herself. You know her best, so choose the subscription that matches her current age and maturity.
No problem. You can switch her to the next subscription at any time from your dashboard, or just message us and we’ll help move her over for the next cycle. The monthly price stays the same for both subscriptions.
Our monthly letters ship during the first week of each month. Before her envelope arrives, the guardian email lands first so you know the month’s theme, what encouragement she is receiving, and what to expect when she opens it.
Welcome letters are sent within about 3 business days of sign-up. Monthly letters are mailed during the first week of each month and usually arrive within 3–7 business days in the U.S., depending on your location and postal timing.
Yes. After you sign up, we send a welcome letter within about 3 business days so she has something special to receive right away. It includes a warm introduction to Big Sister Letters, a small keepsake, and a companion email for the guardian so you know what is arriving.
When you join, you pay at checkout and your subscription is then synced to renew on the first of each month while active. There is a 10-day cutoff before the first of the month for joining the upcoming monthly letter cycle.
If you sign up before the 10-day cutoff, she will receive her welcome letter right away and then be included in the very next monthly letter. For example, if you subscribe on June 15, she would receive her welcome letter within about 3 business days and then be included in the July monthly letter.
If you sign up within 10 days of the next month’s cycle, she will still receive her welcome letter right away, but her first regular monthly letter will begin in the following month so we have enough time to prepare everything well. For example, if you subscribe on June 25, she would still receive her welcome letter within about 3 business days, but her first regular monthly letter would be the August letter rather than July.
Yes. Every letter is written specifically for the age group it is meant for and tailored to what girls in that season of life are actually navigating. Guardians also receive a preview before the physical letter arrives, so you always know the theme and the kind of encouragement she is receiving.
Each subscription is personalized for one girl only, so if you have multiple daughters, each one needs her own separate checkout, payment, and subscription setup. At this time, you cannot add two subscriptions for two girls in one cart, so you will need to complete the checkout process once for each girl so each one receives her own personalized envelope and guardian support.
Yes. Big Sister Letters makes a thoughtful gift from grandparents, aunts, uncles, or family friends. At checkout, click "Buying as a gift" button. Then be sure to enter the girl’s name and mailing address in the shipping information, and use the primary guardian’s email so the grown-up responsible for her receives the companion emails and monthly previews.
If you are the main guardian signing up directly for your own girl, there is no need to choose a gift option. Just enter your email to make the account, then enter the girls name and mailing address in the shipping information.
You can cancel, pause, or renew your subscription at any time through your secure guardian portal.