Freaks out and tries to reverse changes. Realize to late that she can't

"W-WHAT!?!" Mabel shrieks, floundering as her flailing movements pop her new dick out and have it swinging around. Rushing back to the book, Mabel looks down at the rule she made. "This can't be my dream body... right?"

Just as she's about to try crossing out the rule, Mabel see's the last note on the first page, telling her that pen essentially made the rule permanent.

"So, I'm stuck like this?" Mabel wonders allowed as she puts the pen down to avoid making any new permeant rules.