As someone who can relate to your wife, I know she needs help. You need to be there for her if you love her, but you need to help yourself first and get resources you need to help her.

In regards to your saying "At the same time there are just some lines that shouldn't be crossed. Incest as a victim is one thing, mutually agreed upon incest or incest as a perpetrator are both entirely different."
When you are abused as a child, especially sexually abused by your family members it can seem to outsiders and people who haven't experienced it that it was mutual. But that isn't the case. Those children are all victims. You just can't know at that age what is right and wrong, especially if something like that is being forced on you. It fractures your mind. I definitely don't think you can agree on incest ******* unless both parties are legal adults, especially because it's a family dynamic you grow up in. You don't know anything else.

Frankly, to me, it sounds a little selfish because you're saying your relationship is "stained" with an abusive past. It's not your past to deal with, it's her past for her to deal with. Imagine how she feels right now. She told you because she trusts you, it's obviously bothering her, and she probably wants help.
If they are all she knows, it can be hard getting out of that family dynamic and cutting ties with them. I'm currently trying to figure out the same thing, and I know firsthand that it's hard. It's the hardest thing I've ever had to face in my life.

It can take a lot of time, and a lot of talking to understand her. But please be gentle with her and don't force/ persuade her to talk about it if she doesn't want to. She'll seek you out when she needs the help, as she's done before.

Take the time you need for yourself to maybe do research on those types of pasts, to better understand your wife's childhood, and by all means take time to strengthen yourself. Care for yourself. Your health is important, most definitely. but I just urge you to think about how extremely difficult it is for your wife, and don't let this turn your wife into someone you're disgusted by because honestly it's not her fault, and that wouldn't have been love on your part in the first place.