I agree with the above post. I'm the same age as your friend and even though I don't drink so carding doesn't effect me I can't see wanting to look younger. 21 is a strange age where your old enough to do everything any adult can do but your still considered a young adult by many and probably are still considered immature, though I think that comes from the whole legal to drink so you probably are deal. Anyway my point is 21 is the age most people can't wait to reach after 18 of course and I think your friend just needs some emotional support not a spell.
I'm sure your friend is more attractive than she thinks as people tend to look at theirselves more critically than others do noticing all these flaws which others would never notice. In the end the human condition is we either are overly vain and think we look great or we think we look terrible, we rarely find a place in between and often put ourselves down. Just be there for her.