Hmmm, we know all the parents of our daughter's friends so this wouldn't be an issue for me.
In your case, I would simply ask the mom questions regarding your concerns and go from there depending on how you feel about her answers.
We did the hotel birthday party at 12 with a few close friends (6 girls total) We had a limo pick everyone up, drive around town and then to the hotel. The hotel is in a upscale area with lots of restaurants, etc.
I booked a suite. The girls slept in the bedroom and I stayed on the pullout in the suite area. Yes, I was up most of the night as the girls were giggly and having fun. They went swimming, then got fixed up and we walked to a nice restaurant for dinner (hubby came along on dinner) then walked back to the hotel and went swimming again, then watched movies and had late night room service. The girls were scheduled to be picked up by 10am the following morning. About 9am hubby brought in donuts, juice, milk, etc for them.
I am the one who stayed with them 24/7. I didn't let them run the hallways or get ice because I knew some moms were not as lenient as I am .. At that age, we did allow daughter to go get ice and gave her plenty of space within reason. Each family is different so I erred on being on the more strict side vs more lenient side. My daughter understood my reasoning.
Everyone had a great time. Go with your gut on how you feel about the parents of this child. I know it is hard letting go, I am still struggling with that one with my daughter wanting to go to college a plane ticket away and in Italy! I just trust that I have taught her well.