Personally I would just ask her the night before what time she plans on coming in the morning because you are going to be going on outings in the morning and would be away from __ to __ daily. I find that when parents think their child is going to miss out on something they show up earlier.

I have one that is similar although drop off wasn't usually that late. Latest was around 10. I would just carry on with my morning. The boy really enjoys art/craft time so he would ALWAYS miss out. The other kids would show him what they did and I would casually mention him (and mom) sorry you missed art/crafts this morning. He has missed snack on occasion too. Luckily mom's schedule is earlier this time around at school so drop off's are somewhat around 9 am every day now.