Some simple math: One + One + One = One too many! From the day we were born, Mary Ann and I have been best friends. We've always been a two-some. But now, there's a new girl in town, and what used to be just us two has turned into three. If you ask me, things just don't add up!

Mallory starts fifth grade and has to adjust to a new teacher, a tough school project, and trouble with her best friend that involves her brother Max.

Looking forward to a family road trip to the Grand Canyon, Mallory's excitement dwindles when she finds out that her snobby cousin Kate will be coming along.

Mallory can't wait to play in her town's new girls' basketball league! What could be more fun than trying something new and being on a team? But Mallory's basketball career gets off to a rocky start. None of her friends are on her team. And no matter how much she tries, she can't make a basket. Mallory works as hard as she can to improve. But as her team heads to the playoffs, she still feels like the weakest player. Will she let her teammates down? Or is there more to being part of a team than just winning the game?

After having an awful Halloween, Mallory organizes a Thanksgiving food drive at her school, but it is harder than she expects and she has to consider whether she is doing it for the right reasons.

Summer is over and that can only mean one thing for eight-year-old Mallory McDonald (like the restaurant, but no relation) she has to go back to school. But not just any school, a new school with all new kids in it. To make matters worse, her mom is going, too! She s the new music teacher, and Mallory can t think of anything that could possibly be worse until her first day. She has to sit with Pamela, who always says the right thing and steals her ideas. Joey is so busy with his old friends that he has no time for her, and to top it off, she s picked to be an eggplant in the Fall Festival her mom is putting on. It s not fair! What can Mallory do? Should she give Pamela, and her new school, another chance?

When her best friends Mary Ann and Joey get caught up in the excitement of having a new baby brother, Mallory feels left out.

Mallory is in Washington, D.C. with her fourth grade class. She can't wait to see the famous monuments and museums. But from the moment she sets foot in the nation's capital, there's one thing she doesn't see much of . . . her best friend. Mary Ann is spending so much time with the new boy in their class, she's forgotten all about being partners with Mallory. And when Mallory wanders off to wiggle her loose tooth, her tooth isn't the only thing that is lost! Will Mallory's trip to Washington turn out to be one she'll always remember or something she'd rather forget?

Ten-year-old Mallory is not looking forward to the summer as her friends are either moving or away on vacation, but she soon learns that some changes can be good, and some things are forever.

Mallory's new neighbors, the Goldmans, have twin five-year-old boys who need babysitters. Mrs. Goldman hires Mallory and her friend Chloe Jennifer to watch the boys while she works from home. Mallory can't wait! The boys are adorable, so this job will be tons of fun . . . right? Actually, the boys turn out to be a handful. Plus, Mallory has trouble balancing her babysitting duties with her schoolwork, friends, and preparation for an upcoming school poetry slam. Will she figure out how to prioritize the things that matter the most before her new career ruins her life?