Sarah has a major problem in that she won't own that she is a Werewolf, that it's permanent, and the only "cure" she can find will be her own self control.
Lycanthropy can't be cured. If it was curable, a lot of Were-whatevers would have taken the cure already. They haven't.
Sarah is also blaming her 'indelicate condition" totally on Peter. She seems to have forgotten she said "yes".
Nasty word, "yes". It confers responsibility, which she has avoided all her life.
Now she's stuck with responsibility for what she is and has become; and she isn't accepting it at all. I suspect that's one reason why the Wuff is so hard to control, among several reasons. There is also the reason that the Wuff has fun doing things, and she doesn't; unless it is something carefully scripted and under her control at all times.
That's what she's doing with Peter. He's her excuse for... And he has been "trained" into accepting that role in relationships.
These two kids need to grow up fast, before things spiral even farther out of control and the Wuff starts taking over Sarah. Yeah, that...