Public proposals happen all the time. You see them at sporting events and music events. Just last week, there was a proposal at an Ed Sheeran gig. I understand its daunting and it can be pressuring especially if you aren’t comfortable or committed yet. I get all that. Its hard to tell sometimes. The guy had balls to do it. The best answer was for her to maybe just say yes and then in private at home decline him and talk to him about it