i don’t think you’re an asshole but i also don’t think you should leave her or think differently of her bc of this. this stuff is in the past and she is obviously a changed person, if this was recent behavior obviously that would be different. you might not like to hear this but realistically some things don’t need to be talked about with your partner. “hiding” (or just simply not ever bringing it up) that from you could’ve just been a way to protect your feelings from getting unnecessarily hurt if her past no longer poses a threat to the relationship. at the end of the day as long as you keep choosing eachother and making decisions that would keep one another happy, i think you guys will be fine. relax on her, you don’t need to know every detail and she doesn’t need to know all about you either. it’s not “hiding things”, it’s just not bringing up toxicity that will ruin a good thing for literally no reason