I am so sorry to hear about this. But don't give up. It always feels more difficult and stressful in the beginning when you're first setting up and trying to get parents.

Unfortunately, this parent really over-reacted. Most of them understand that it's an adjustment for your own children. I explain to parents, that often the relationship between their children and my own children become like a sibling relationship. They can play great most of the time, but then they can fight and argue and say things. These parents will witness both. My kids somedays will still say things...it happens. Often for me it's my 5 year old getting grumpy at the end of the day, wanting the kids to leave and sometimes saying things to parents. I always correct her behaviour, but I also understand where she's coming from and so do my parents.

Perhaps this parent just wants to be reassured that this doesn't go on all day, or she's having other issues, separation anxiety since this is new to her.

Don't give up though...we all go through this at one time or another. Good luck, keep us posted.