Yes i do the same as Mom of 4 said - I empathize and say that I have been there and know how hard it is but that eventually LO is going to love daycare. I remind the parents that it is just a transition period and that I am totally expecting there to be rough days at first and that the rough days are perfectly normal.

I try to seem and sound confident and every morning assure them that LO will be okay and fine and that we are going to have a good day.

I have emailed during nap time to a nervous parent to assure them or send them a picture. They really appreciate that and always feel better.

Reminding mom to keep drop offs/goodbyes brief in the morning should also make it easier for her and LO