Go 'head, Strive!
@Babyblue---when you say clothes/hairstyle, what do you mean? Are her clothes/hairstyle outdated? Disheveled? Ill-fitting?
Is she going through some things at this time?
Maybe you could suggest a girls night-out...take her to a MAC cosmetic counter and they can give her a makeover and compliment her on a certain attribute ("I wish I had your skin/eye/cheekbones---I think this shade would really play it up").
Go shopping and suggest some items ("girl, I think this color would look so cute on you!!")
Ask her to go walking/working out with you girl ("ok....divas need to be summer-ready, let's go walking on our lunch hour").
You can be helpful and affirming at the same time.