In the Purple Berry Puffs cereal commercial she eats some cereal and gains a lot a of weight from it. In the second commercial she says "I don't know which I like more; original or type two", referring to diabetes. It is possible she has diabetes from her reference. She has brown hair.
Cereal Girl: Mom, why is there orange in my Purpleberry puffs?
Cereal Girl's Mom: As an active Mother I care about these things. I'll check the box while you start eating?
Princess Purpleberry: Now my Sugar-Blasted purpleberries have Loquat-Flavored orange berries.
Cereal Girl: Two colors, Wow! (Scene flashes and she gains weight) (burping) Bort.
Zoidberg: It's a small part of this girl's breakfast.
(The bubble he's in pops)
(Cereal Girl and her Mother laugh)
Cereal Girl's Mom: You can really see the sugar!
Cereal Girl: I don't know what I like more: original or Type Two.