Any ideas, modifies, changes, for this spa party?

Im kinda planning this party for my younger sister (she’s turning 11). And this is what we are thinking about doing:
http://gocitykids.parentsconnect.com/attraction/teen-spa-diva-parties-at-kai-227-sandy-springs-place-suite-388-atlanta-ga-30328-us

Any ideas to add to the party? Any modifies? Oh and by the way if you choose to tell me how i can add to the party the budget is $50. Oh and I would love some cool ideas for invites!