I think that is ridiculous Lynn.. First of all that would be crazy to hold a grudge just for that potty training issue and I can't even remember that time in my life.
I don't remember potty training because I was way too young to remember something like that and I am sure that she probably don't remember either. Even if she did remember what is that to hold a life long grudge about!
As far as the molesting part of the issue, I would definitely look in to this because your daughter(s) would have no reason to lie about it. I have heard of way too many adults who don't trust there children about family members or friends molesting there kids. I would definitey be angry at my mom if I she did not believe me and didn't put a definite end to it. Did you talk to her father about these issues because I would have and I would have done something about it because most of the times the mollestor will lie, not saying that this is your case but you always have to believe your children and put them first and admit to your mistakes as a parent.. even if they are wrong apologize anyway.
I know that you are probably upset that your daughter is accusing her dad of something like that but she must have a reason.. Maybe she was mollested by him at a young age or she doesn't trust him and is not close to him. If she was closer to him and trusted him then probably things may be different but if you don't take her side and believe her, and accept her wishes than I honestly do not blame her for this. I mean things happen and you may never be close to some of your daughters and for this you need to think something is up if 3 of your daughters do not care to see you. I don't want to seem harsh but that is a fact. I wish you luck and pray that you will find a way to heal all past wounds.
I have confronted my mom on some issues that I had as a child also and she said that she can't remember anything but my mom has apologized or I would probably still be a little upset about some things that she has done. My mom didn't do anything horrible but I have some grudges over my mom putting my brother first and all.
My mom finally admitted this because my brothers father had main custody and my mom didn't get to see him as much as she saw me. Always know that how you treat your children will come back to haunt you and treat all of them equal and show lots of love and definitely don't let anyone hurt your children because later they will hold a grudge for a long time or indefinitely.
Hope the info is of some help...