I’m sure you could get 10 different opinions on this if you asked 10 different experts but it’s my opinion to leave well enough alone and move on from here. In my experience of working with kids of divorce (and parents) the younger the kids are, the more resilient they are. Kids can tolerate change very well at this age. The other advantage is that most of us typically do not have specific memories until we are about 4 or 5. So your daughter won’t remember the specifics of you and her father living together when she looks back on all this later. She will remember the situation you create for her.
If you really feel the relationship is over, I would just accept it, move on and work on co-parenting skills. She will be harmed more by a back and forth pattern and instability than she will by a clean break. Sounds like your parents are helping bridge the gap, which is great, but be careful not to let them take the place of her father. Make sure you prioritize her time with him and let him begin to establish some new patterns with her as well. There are many good books on navigating divorce and I’d suggest checking out the bookstores and libraries for kids books on the subject as well. Good luck with your situation.