As Jen starts to play with herself changes were happening inside her body from the curse as it tried to figure out the wording and intent of both the caster (Kyle) who wanted revenge and his poor wording and the recipient (Jen) who found the loophole fast and was thinking of abusing her new powers, so the curse found a middle where both would be somewhat happy with the results with Kyle getting negative things happening to Jen and Jen still getting the power but not being able intentionally change something she "finished" with, so Jen would permanently have melon sized breast and butt until she swapped with someone else, the problem for the curse to fix was the one in her womb as she had "finished" with it bot had not directly connected it to herself.