I mean it depends how it happens and how she treats it. Like if it was clearly an accident and she didn’t know, and she was sorry for it, I would forgive her. If it was something she’d been warned about and was just careless, and she tried to downplay it as just an ‘oopsie’ and no big deal, then I’d feel like I couldn’t trust her with anything important and that’d probably be the death of the relationship.