Should i be worried about my 18year old girlfriend going to a 'school disco' style event at university?

Its one of her freshers week events. We have been going out for nearly 2 years. Like you know how the girls dress up and that for this sort of thing - doesn't it have a 'vibe' for single people? Is it right for her to go? In fairness her mates have boyfriends and are going too. Opinions please