I do think it has gotten worse due to the punishment DF did.... and when she does it he gets so angry at her. I think cause she acts so grown up, he forgets she is still just a baby really
You mentioned that you and your partner went through a rough patch - even though it was a while ago and only for a short time. Children are so sensitive to their parents interactions and emotions etc, they can pick up what we think we are hiding so well. This may seem a bit different but what gets rewarded gets repeated - so if your little one gets a huge reaction from weeing wherever, whenever, even if it isn't great attention, she could be just after some added reassurance so will go for it however she can.

Please!!! There is no way I am saying you're a bad parent because just reading your posts, you are not!! You are a wonderful mummy looking after your little one But I have found with my girls, if DH & I have a moment, and we've had those that last for a week or so, my girls behaviour changes. Just today, DD#2 is in a 'mood' as we are paying lots of attention to DD#1 as she is vomiting and really sick today - DD#2 doesn't get that her big sister is sick, just that mummy & daddy's attention is more elsewhere.

Does all that make sense??

I am no expert, just a mummy whose observed her own little ones so all this woffle may not even apply, but it might be worth considering along with the medical options (infections etc). So all I'd suggest would be going back to when you trained her and massively rewarding her for her successes and simply changing her, as unemotionally as possible (easier said than done as my eldest has had those inconvenient accidents just because she didn't listen to her body!) and moving on.

I got this great DVD to teach DD#1 to pay attention to her body and it was simply "Bear in the Big Blue House - Potty Time" - Tutter wants to play checkers but is wriggling everywhere coz he needs to go to the toilet, OJ has an accident because she waited to long and I just love how Big Bear talks to your child and the characters about listening to your body.

Anywhos, hope you don't mind me sharing and maybe even hope it helped you a little.