Yeah, if you think you might have a flashback, dressing up as a bloody prom queen might be a bad idea? It's up to you though, whatever you feel comfortable with. You could be... Cinderella? It's a similar story, but not bloody, plus you can wear a pretty princess dress?
We usually had a parade too... OH we could go to a parade! They do that in some cities, and it's nothing like prom.