Asking that question on Macrumors invites answers from tech geeks. Considering a new MBA may be released in less than 2 months (beginning of june), I would strongly recommend against getting a 2013 MBA right now, if not to get the new iteration, but at least to get a better price on the old model. This is only my opinion, and if she really needs it right now, I would get a rMBP for 150$ more. Just please, don't get a 2013 MBA, which hasn't had a major redesign since its conception in 2008, two months before a major redesign! Granted, there may not be a redesign, but it seems as if there will be.
TL;DR: Wait until June, unless you can't.