That’s very true, but I also think if you’re going to propose to someone you’d probably better have a good idea that she’s going to say yes, and have discussed marriage with each other before. The method of proposal can be a surprise, but the proposal itself really shouldn’t be.
To the OP- you know your girlfriend better than any of us. If she doesn’t like the limelight, definitely don’t do it in front of anyone else. I sort of ruined my husband’s proposal plans (unintentionally…I had no idea he was planning it on the particular day he was) so it didn’t go “as planned”. But it was still nice and now we have a funny story.

Don’t stress out too much about it- if she wants to marry you, she’ll say yes and won’t really care if the proposal is something out of a movie or not. Best wishes!