My daughter hasn't been using the day care toilet for poo-poo. She is otherwise potty-trained. I think it has got more to do with the security and comfort. Any tips on how i can convince her to start using the school toilet?

It could be due to the different toilet routine between home and school. Try to talk to teacher in school what is the routine and see if any modification and adjustment can be made e.g. take the child separately to toilet at certain timing instead of following group. The other reason could be due to different toilet setting between home and school. If you are using potty at home, you can slowly train your daugther to use toilet seat.