Hi Secretworld, both myself and my partner self harms which makes our relationship a very volatile one, but as both a SI er and the partner of someone who has struggled in the past, I've got to stress that unless you physically harm your wife, whenever she cuts or harms herself it is not your fault. A lot of people SI when they're feeling distressed, angry, alone and unable to cope with a situation, so if you were to argue as a couple, it is likely that her SI would be her way of dealing with it. It's not healthy and shouldn't be encouraged by any stretch, but you should realise that, while you should be accommodating and understanding of the self harming, sometimes it's not possible to not be in a difficult situation within the relationship and not act a certain way in fear of your wife SI ing. Because you have emotions too.

I think one thing you could try is maybe talking to her about it when she is calm one day. But I'd say just be careful not to make her feel guilty, because from personal experience, it can put an extra pressure on her if she feels like reacting the way she finds works for her is going to cause damage to her relationship. It's a difficult scenario.

I hope both you and your wife are well and figure something out. It's a fine line between helping and making worse and unfortunately that line is different for everyone, I think.
Good luck.