Both of my children have issues of jealousy with the daycare kids sometimes...however, as much as they are allowed to own their feelings, they are not aloud to physically or emotionally hurt another child because of their feelings...I have had to explain to my 4.5yo dd that if these kids aren't here that means mommy has to go back to work and she would have to go to a daycare. My 2 yo gets jealous of mommys time as well...Ive allowed him to go to his room when he needs space or have his special toy/ cup/ book that is only his not the daycares so he doesn't feel so invaded....To be completely honest, your daughter needs to learn to deal with emotions in a more productive way...kindergarten isn't that far away and I think having other children to socialize with and especially children she doesn't necessarily get along with, is a positive thing. There will always be people in childrens lives who they may not like, but they do need to learn a productive way to deal with them. You can't shield her forever. All that will do is prolong the inevitable and cause her a more inability to cope. Good Luck