Hi M. - Two things come to mind from my potty training history - lol.
1. I am potty training my two year old right now...he's not a fan of the toilet at school. The teacher said he shakes and she won't make him go on it - because she knows he's scared. So to handle this, we've just decided that we were going to not change anything with re: to him see and trying to go, she doesn't make him, but just the repetition of asking and him seeing others go, in addition to him getting out and around more toilets, it has helped him to overcome this fear, and he's now going. SO, I am not sure if she's having an issue with the potty or something is bothering her about the toilet, but if so and she says so, I would just keep comforting her and addressing her fears with the daycare.
2. My older guy, when he was 3 1/2, was fully potty trained, then had a period where he pooped and peed on the floor, right next to the toilet. Granted, I had just gotten pregnant, but, either way, we still had to handle this. He reverted, is what my docs called it, and their suggestions were NOT TO WORRY about it, to handle each situation with a reminder about going in the toilet, to have him help clean up and to keep him focused again on going (so kinda of like re-potty training him) until he started going again, in the right place :). It really wasn't long that this persisted, maybe a few weeks, and then he was over it.
Suggestions...don't get frustrated, keep her in pull-ups, make sure the daycare is aware of her normal bowel movement times so they can get her on a toilet, and just take each day seperately...she'll get it. Each kid is different and this is just something (for some reason) that is reoccuring that she is still just working through. I think being real with her, in addition to talking her through what you are needing and thinking with her is important, so then you are both clear on what the goal is. Even at 4, they understand trying and understand your need for things. She'll pick up on your love, understanding and extra effort and I'm sure she'll be back to getting ALL her stuff in the right place.
Good luck!