She isn’t the problem he is. If she didn’t exist he’d find another way to hurt you.

Cut contact, he’s keeping you as his backup. Even if he did someday leave his partner and offer you everything he’d just find another backup to have behind your back. He’s just one of those selfish, manipulative, lying people.

Hopefully she can drop her defenses and hear you, best of luck

No, they don’t, she just has an asshole of a husband.

It’s up to you if you want to repair the relationship or not. If you do I would type a heartfelt email (or just write up points you would like to bring up and do it on the phone) and explain to her how her actions were harmful and how her response was also a problem, that you understand it isn’t easy to be told you said something wrong but she still needs to take accountability. If she can take that like a mature adult in a way that satisfies you, then maybe you’re on the road towards a stronger relationship, if she gives you more of the same, then it might be best for you to distance yourself. I’m a white woman and her age and I certainly know better than to say something like that, she is old enough to be responsible for her actions and to take this as a learning experience. She might not have intended any harm but she is an adult with family who are affected by her comments, and she needs to be more cognizant of what she’s saying.