I have hosted two showers at Trailhead Brewing Co in St. Charles if you're looking to have the shower at a restaurant. Great food, small rooms that they can reserve for you, great service. Good luck!
We just had a bridal shower for my sister at Pietros in South City of St. Louis. I am not sure how it would work with 10-15 people, because we had 40. I am sure they would be willing to work with you though. The food was great, service was good, and everything, including drinks, gratuity, and taxes were included in their price, so there were no suprises when the bill came.
Re: Shower Locations
I have hosted two showers at Trailhead Brewing Co in St. Charles if you're looking to have the shower at a restaurant. Great food, small rooms that they can reserve for you, great service. Good luck!
https://www.trailheadbrewing.com/