did you potty train her? Seems NOT

Perhaps she's just not ready yet hunnie? My daughter was fully potty trained just before her second birthday. However my son is 2 and a half and he's far from ready. They'll be ready when they show an interest in the toilet. Perhaps take her in the toilet with you to encourage her (don't worry she won't remember).

This to me sounds more of a psychological problem. Are there major stressors in the environment? [New boyfriend, fighting/arguing with dad, other people with visible stress?]

This to me sounds like a potential source of the problem. I've been a sounding board for my wife, who's a psychologist, for 8 yrs. but I'm DEFINITELY NOT trained myself. I would consider making a pact with him to not fight in front of her. We postpone fights until my daughter's asleep, which isn't always easy, but we do it for her. It would be nice if he could make the sacrifice to make more time for her future psychological health, but honestly the anxiety that she experiences through seeing you fight is a more immediate concern. Do you make up, ever? If so, let her see that there is love between you. Let her see that even if fighting occurs (because it's human to do so) that there can be resolution and reconciliation. Showing her that there's affection between the two of you (if that's possible) can relieve the sense of impending schism and instability cause she'll see her stability is not coming to an end. Also make sure she's getting frequent affection too. It's easy enough to neglect and I've been guilty of lack of affection sometimes especially when I'm emotionally upset. But I remind myself to put her emotional well-being before my own emotional turmoil and do an emotional "change-back" I hug her and tell her that I love her. In the end, I end up feeling better. Sorry for the looong answer, but your situation seemed kinda serious. If you want some more free advice, feel free to email me (my address is in my profile). I can bounce some questions off of my wife and see what she recommends. Hope this helps.

Take your daughter to a doctor and see if together you can pin point a problem. There may be many reasons for it; anexity, lazy, can't contol her bladder and bowel movement you can take all the advise of people on AB but only a doctor or therapist can assist to get down to the bottom of it. My oldest child use to wet the bed until she was in the forth grade it turned out that she was lazy but it was only months of observation and patterns that we figured that out. Each child is unique therefore seek a professional.