Seeking restaurant with private-ish room

I'm looking for recommendations for restaurants in CoMo that have a small private-ish room to reserve. I'm planning to host a surprise party for my mother's 70th birthday. It will be a small group of just the kids and grandkids, only about 12-15 will be attending. Hoping for a room I can reserve and not pay extra for. We will be buying food and drinks.

I'm not from or familiar with CoMo, it just happens to be a good central meeting spot for us.

I appreciate any suggestions and tips.