In Sofia's words . . .
Mia St. Claire is only the most popular girl in all of Middlebrooke Middle School. For three very obvious reasons:
1. She's very rich.
2. She has tons of money.
3. She can buy anything and everything she wants. And she does.
I'm sure people like her for other reasons too, but none of those reasons are obvious enough for me to really know. Or care about, for that matter.