Start by asking her why she feels as though she needs to do this.
Then address that first. Make her feel beautiful and tell her to try to stop, for you. Make her a promise. You'll stop doing something that bothers her, if she stops this.
Make sure you don't come off as judgmental, only concerned. Don't force the idea on her.
But if this doesn't work and you still are really worried about her tell her how concerned you are. Tell her that you don't like to see her doing this to herself and that you'll have to take other steps. Such as telling someone, only because you care. Again don't say it angrily, be kind and gentle.
PM me anytime.
Are you always sad? Someone asked.
(Always is such a long, long time)
I couldn't say. But
If sadness was a sea, I'd drown in it.
(Salty and warm, sadness is.)
(Cold, too. Sometimes)
And I happen to love the sea.
And I watched your words burn tiny holes
into my retinas. Just wide enough to crawl into,
And forget you ever were.