Domestic violence can be used in divorces involving property division if it can be shown the the resulting violence prevented the victim from working or contributing to the martial community. Proof of the DV can be used to make a disproportionate division of property. Beyond this, since Wa. is a no-fault state, the court doesn't care why you are getting divorced or even what happened, their singular purpose when there are no kids involved is to make a fair just and equitable division of marital property. Of course, if there are kids involved then the allegation becomes important. She would need to show a pattern of DV rather the one isolated incident.