I have not been in a few years, but I loved Marchetti’s in Cranston, RI. It is Italian, and I do not remember how vegetarian friendly it is, but the food is excellent. The decor is a little cheesy, but you don’t need to live there, you are there for the food. Strongly recommend.
Make reservations ASAP. Since you have a fair number of people in your party,you might want to look for a restaurant with a private room. My D graduated in 2019 (MFA Brown/Trinity) and we went to Gracies after the ceremony. My D was in a number of shows at Trinity Rep, so we were in Providence fairly often. Some of the restaurants we liked: Persimmon, Oberlin (mostly small plates), Waterman Grille (has vegetarian options), and New Rivers. Al Forno has great Italian food–only ate there once. It was difficult to get reservations. Enjoy!
My sister lives in Providence. Her favorite restaurant is Al Forno and I have been there a few times. It’s also Italian and is excellent! Everything I’ve eaten there has been amazing!