If you like Bras and Broomsticks by Sarah Mlynowski
In case you don’t know, it is the first in a series (Frogs and French Kisses; Spells and Sleeping Bags; and Parties and Potions). You mention liking books about growing up but that you also like fantasy. Since Bras and Broomsticks is about a modern teenage witch, it has a little fantasy and a lot of modern humor. So, I wasn’t sure if you wanted something modern and funny or something fantasy about growing up, so I’ve included both:
Clique by Lisi Harrison.
Head-to-toe Calvin Klein is in. So is Ralph Lauren. Burberry is so out. And as for Claire's platform navy Keds and two-year-old, white Gap jeans--doesn't she know that clothes are like milk or cheese with a "best-before date" and a limited shelf life? Claire is clueless when she enters seventh grade, a newcomer and total outsider when it comes to [...] Massie's friends at an exclusive private girls' school. Massie leads her clique in humiliating [Claire] (including splashing those jeans with red paint to make it look like Claire has her period), and the instant messaging is very mean.
Mates, Dates and Inflatable Bras (Mates, Dates, series) by Cathy Hopkins.
At age 14, Lucy looks 12, while her friends Izzy and Nesta can easily pass for 16-year-olds. Lucy experiences bittersweet emotions as she sets her sights on a boy, makes difficult decisions, and copes with a new girl becoming part of a longstanding friendship. There's humor aplenty as the girls resort to tarot cards, discover inflatable bras, and get bad haircuts.
I’d tell you I love you, but then I’d have to kill you by Ally Carter.
Cammie Morgan, 15, is a student at Gallagher Academy, a top-secret boarding school for girls who are spies-in-training. She studies covert operations, culture and assimilation, and advanced encryption, and has learned to speak 14 languages. Her troubles begin when she falls for Josh, a local boy who has no clue about her real identity. Keeping her training secret forces her to lie to her new love, which leads to comic complications.
Secrets of my Hollywood Life by Jen Caolinta.
Kaitlin Burke is an overworked teen celebrity who thinks it would be cool to be ordinary for a couple of months. She also wants to get away from her competitive costar, Sky Mackenzie, who has been making her life difficult. After a bit of brainstorming, she decides to enroll, incognito, in her friend Liz's high school. During the next few weeks, she discovers how nice it is to have friends who like her for who she is–or appears to be–rather than because she's famous. She even starts a relationship with Austin, a nice boy who, ironically, has a crush on Kaitlin Burke, but hasn't a clue that he's dating her.
How to be Popular by Meg Cabot.
Tired of being known only as the girl who spilled a Big Gulp on the most popular girl in school's white D&G skirt in sixth grade, high school junior Steph hatches a plan to become popular. Soon, though, Steph discovers that the love of her life is not sitting at the popular kids' table in the school cafeteria.
All-American Girl by Meg Cabot.
While waiting for her ride home from an after-school art class, Samantha Madison, a sophomore at John Adams Preparatory School in Washington, DC, inadvertently saves the President's life by jumping on the back of a would-be assassin. Suddenly, she is a celebrity, invited to the White House for dinner, named the teen ambassador to the U.N., and revered by her fellow classmates. Yet, even her new star status doesn't allow her to get what she really wants-a date with her sister's boyfriend, Jack. Hoping to make him jealous, she asks out the President's son. The plan backfires, but Samantha discovers who she really is in the process.
Alanna: The First Adventure by Tamora Pierce.
Call it fate, call it intuition, or just call it common sense, but somehow young Alanna knows she isn't meant to become some proper lady cloistered in a convent. Instead, she wants to be a great warrior maiden--a female knight. But in the land of Tortall, women aren't allowed to train as warriors. So Alanna finds a way to switch places with her twin, Thom, and take his place as a knight in training at the palace of King Roald. Disguising herself as a boy, Alanna begins her training as a page in the royal court.
Bella at Midnight by Diane Stanley.
A baby girl, Bella, is born to a mother who dies in childbirth. Bella's furious father sends her away to be raised among peasants, where she is befriended by Julian, a prince, a fourth son who has no place in his family. When they are both teenagers, Julian treats Bella cruelly; then he is sent away to a warring kingdom as a hostage for peace. Soon after, Bella is recalled by her father and finds herself unhappily living with him and his new family, including a stepsister who is a handmaiden at the palace. It is from this young woman that Bella learns about an invasion that will bring about Julian's death, which Bella is determined to prevent.
Ella Enchanted by Gail Carson Levine.
At birth, Ella is inadvertently cursed by an imprudent fairy named Lucinda, who bestows on her the "gift" of obedience. Anything anyone tells her to do, Ella must obey. Another girl might have been cowed by this affliction, but not feisty Ella: "Instead of making me docile, Lucinda's curse made a rebel of me. Or perhaps I was that way naturally." When her beloved mother dies, leaving her in the care of a mostly absent and avaricious father, and later, a loathsome stepmother and two treacherous stepsisters, Ella's life and well-being seem in grave peril. But her intelligence and saucy nature keep her in good stead as she sets out on a quest for freedom and self-discovery, trying to track down Lucinda to undo the curse, fending off ogres, befriending elves, and falling in love with a prince along the way.