Royal Crush (From the Notebooks of a Middle School Princess, Bk. 3) by Cabot, Meg-Hardcover

Olivia Grace Clarisse Mignonette Harrison is turning thirteen. Even better, she's finally starting to get the hang of this princess thing. Just in time, too, since her half sister, Princess Mia Thermopolis, is expected to give birth to twins any day now!

It's pretty much the worst time possible for a school field trip, but Olivia must attend the Royal School Winter Games. Between Grand-mere chaperoning, Olivia's snobby cousin Luisa complaining about her relationship woes, and everyone insisting that Olivia has a crush on Prince Khalil (even though she isn't sure that he even wants to be friends anymore!), things are quickly turning into a royal mess!