We used to sign up sk every summer for the daycamp our city offered. and while they are with us there address IS our address.
We used ours as cheap daycare and the kids had fun doing activities instead of just sitting around the house.
AND if they are attending during her time, she should be the one to be contacted if there is an emergency. If your dh wants to be contact as well that's fine but the parent who has the child for that time should be contacted first.
Even with Sole legal the NCP can and should be able to have the kids do activities THEY deem appropriate. she is still a parent and has not had her parental rights revoked.