Whether from bad habit or separation anxiety (or a combination of both), ITA with the others about a very short and sweet goodbye. It's like pulling a band-aid quickly of slowly - slowly is worse because there is always the secret hope by the distressed child that the parent will "rescue them" (as they see it).

If you have the choice for her dad/other caregiver to drop her off - it sometimes works wonders. Another thing you could do is have a teacher meet you at the car.

I so identify with how hard this is. I think most parents understand and think little of seeing another child upset at a goodbye.