It came from her aunt's boyfriend, and she struggled hard, scratching and kicking, before she finally managed to push him away. When she told her aunt about that, and about the other things he did later, the woman slapped her and accused her of lying.
That was why she ran away.
Her first kiss as Anaesthesia came from a sweet Ratspeaker boy. She really liked him, and his kiss was much more gentle. Nevertheless, she had to explain her tears away as joy that he liked her too.