TNL:Uh-Oh

"How could I be so stupid" Jack thought. He was now a good-looking girl in early highschool. Possibly 14 or 15.
"How much mashed potatoes did you used?" Asked Jill.
"I didn't think I'd turn out like this" Jack replied.
"You're gonna have trouble with bras, You're only 15 and you're already bigger then I am." Jill stated. "I'd say about a DD."
Jack fell down onto the couch. (S)he felt like (S)he was going to cry.
What is (S)he going to do?