The Princess Diaries 3 & 4 Bind Up by Meg Cabot
Mia might be the heir to the throne of Genovia. But right now there's only one thing that REALLY matters - her love life. Total hottie Michael is so the only guy for Mia and she's finally got him sussed! Then along comes Grandmere to royally interfere . . .
Contains The Princess Diaries: Third Time Lucky and The Princess Diaries: Mia Goes Fourth.