R.Q.
She just wants attention. When the parent split up, its hard for the kids as well no matter what the age is because they are use to both parents under the same roof regardless of you did the most work at home. It will take time for her again to potty train so just start all over again. Let her sleep in bed with you at times for this is rough on her too. Dont fight with your partner in front of her because that will led to more issues for you lil girl. Keep doing what you do best and thats taking care of your family. I am a mother of 3 and divorced and I try hard to give them a positive atmosphere. So I know how you feel when things get out of place with the kids. Just start all over and comfort her and show her attention and she will get back on it. Give her praise for going and dont critisize her. good luck and god bless!!