(CNN) When author Naama Bloom watched her hilarious "Camp Gyno" video, about a tween who is the first girl at her summer camp to get a period, go viral in 2013, she knew she was on to something.
She received thousands of emails from girls and older women, and she heard from moms who said that the video led to hourlong conversations with their daughters. Some girls were even watching the video, which has now been viewed more than 12 million times on YouTube, at slumber parties.
The sequel "Full Moon Party," about a girl who fakes getting her period and then faces the consequences when her mom throws a "first moon party" in her honor, has been viewed more than 42 million times.
The videos were sparking a "mini-revolution" among young girls, said Bloom, founder of HelloFlo, which started as a subscription service offering monthly packages of tampons and pads and has evolved into a media company providing content on health and feminism. "I just kept thinking to myself, 'how is it that a two-minute video is doing this?' "
It was certainly an unusual way to approach conversations about puberty, but the reaction proved to Bloom that the time was right to change the way we talk to girls about it.
And so she decided to write a book, "The Guide, Period." out this week in the United States, aimed at girls who are close to or are going through puberty or have gone through it. It's a book, she says, that is designed to empower women during a time when too often young women feel uncomfortable, ashamed and embarrassed, and it's a book I most definitely will be giving to my daughters.
"My dream is that girls feel very confident in their bodies and feel like they love who they are and how they look and what their body does," said Bloom, who has an 8-year-old daughter and 6-year-old son. "I just want to have these open conversations so that they know that there's nothing shameful about their body."
One way she tries to do that is provide something you don't typically see in puberty books: cultural and historical context on such topics as breast size, body type and pubic hair.
"We felt like it would be really powerful for girls if they understood that so much of what we see and what we perceive as the expectations for us on our bodies is driven by media, and it's almost arbitrary. It's trend-based," said Bloom, who is now vice president of brand marketing at Zulily.
For instance, an illustration on pubic hair takes us from Ancient Egypt, when hairlessness was considered normal; through the 1960s, when women typically had a lot of pubic hair; to early 2000, when hairlessness became more popular again. Pornography is believed to be behind this latest hairless trend; women are often influenced by what they see and what they believe men expect to see and not see.
Bloom remembers how when Kim Kardashian West set the Internet on fire with nude photos in 2014, she was hairless. "I saw that as a grown woman and a mother, and I kept thinking, 'Wow, my daughter is going to grow up in a world where she thinks hair isn't supposed to be on your body, and she's not going to know that this is an aesthetic choice, and choice is the most important thing,' " she said.
"She may choose to be hairless one day, but I want her to know that's a choice."
There are certainly other puberty books available for girls. American Girl's "The Care & Keeping of You 1" (for younger girls) and "The Care & Keeping of You 2" (for older girls) are very popular. But what Bloom wanted to do was delve into what's behind the emotional changes that are going on during puberty, which aren't often discussed.
"I think a lot of books say, 'You may have emotions during puberty,' but they don't explain brain development. They don't explain the fact that friendships evolve during this period. It's a very big moment in time, I think, for girls in particular with their relationships with one another," Bloom said. "I don't think it's a coincidence that the reason why times get tough for girls and boys, I think, during that age is because of puberty."
In a chapter titled "All the Feels," she talks about how a certain amount of worry and mood swings during puberty is normal.
"All the things you're worried about are probably being worried about by many, many other people right this second," she writes. "You think you're too weird and no one has ever felt like you? I'm sorry to tell you (sorry, because I know that sometimes it feels good to think you're the only one ever) but someone out there has felt exactly what you're feeling right now, and has been worried about the exact same thing. In fact, probably more than one person."
This is not a "don't worry; puberty is a piece of cake" book, because we all know it's not. It can be hard, scary and confusing. I remember going from one of the most flat-chested girls in my glass in the ninth grade to having large breasts (too large!) a year later, when I got my period. I hated the way my body looked and how quickly it changed.
"Insecurity really develops around this age, and I felt like I needed to deliver the message that 'you are you, and you may get insecure during this, but take it from me, and take it from all these other women and girls who have given you quotes in this book, that it's temporary,' " Bloom said. "I really wanted to hammer home for them that 'it's not just me saying you're a great person, but it's natural to feel uncomfortable, but it's also so important that you understand that this is part of life, and you are still great, and you will get through this.' "
Bloom said what was really important to her was not to "sugarcoat" things. "I remember not liking the way it felt when people saw my body while I was changing. I remember it clear as day," she said.
Her book features testimonials from girls. One, named Maggie, talks about getting really angry when she realized she couldn't go shirtless like her brother. "My brother came home and said, 'You know you can't do that anymore, right? You're going to get boobs,' " Maggie remembered hearing after she took off her shirt and marched around the house on a hot day. "I knew he was right that I'd get them, but I was so mad that I didn't have any control, and that I had this predestined future."
Bloom said she doesn't remember feeling angry when her body was changing but remembers wanting to wear big-fitting clothes. "It felt like my body was giving away secrets without my permission, and I didn't want to tell these girls that that doesn't happen, because it does," she said.
Bloom said that her book is for girls ages 9 to 14 but that parents know their children best. Girls younger than 9 who are exposed to more may be ready for it, she said. "The second (a young girl) can look on Instagram on her own and have access to the Internet, i think it's important for her to have this book," she said.
As we know, kids are being exposed to porn, even unintentionally, at younger and younger ages. According to a 2007 study in Pediatrics, 66% of Internet users ages 10 to 17 who said they viewed porn online over the past 12 months said they weren't looking for it and saw it by accident. Bloom tells the story of a high school girl who wanted to send a friend a picture of a cute teenage boy. When she typed "hot teenage boy" in Google, she was inundated with porn ads.
"It's even the sort of innocent searches that may lead you to, you know, a not so innocent place, and that's why I think books at this age are still so super important," Bloom said.
Some good advice is for parents to read "The Guide, Period." before giving it to their girls, both to determine whether they are truly ready to read it and to anticipate any queries that might come up.
"We worked really hard to answer the questions in this book and to give examples from girls and other women, but I think it's really critical, especially with topics like this, for parents to know what questions may arise and to be prepared," Bloom said.
Besides giving girls historical information to put in perspective societal pressures about women and their bodies and the knowledge about the emotional changes they may be experiencing, Bloom does something else: She makes it clear her book is for every girl.
A medical drawing features the breast of a black woman. "When have you ever seen a medical drawing where it's not a white person?" Bloom asked. Illustrations show white girls, black girls, Hispanic girls, Muslim girls, a girl with a prosthetic.
There was a "conscious choice" regarding diversity. "We very much wanted it to be clear that this book was for everyone and that every girl could see a representation of herself in the book," she said. "Puberty is universal."