At least she's on the mend. My guess is that she needs to keep
her mind off her own image, or at least be more occupied with
things around her rather than herself. If she frequently watches
shows or read stuff with content like models, fashion, and etc, it
will not help at all, so let her know it would be good if she can
shift her interests to other more... substantial... content like
Time or NatGeo (at least if she's bored by Times the pretty
pictures and stories in NatGeo can interest her). Last thing she
needs is more fashion magazines to sway her. OK maybe she's not a
fashion mag person, but just in case she is.
She would probably falter and deteriorate again. That's
common... no one said it's going to be easy. The most you can do is
just stick by her throughout the whole thing. Keep encouraging
her.
If things get really bad, seek help
I've known people with eating disorders, saw one shake off the
disorder completely. This one went to hospital. She used to shake
her leg a lot while sitting so she can 'get rid of calories' while
not doing anything. After hospitalization and help from my mother
(who is her good friend) now she's an entrepreneur and she
managed to get a boyfriend. See? Eating well and being
busy with achieving your dreams make you look more attractive than
one who throws up in the toilet frequently. I honestly don't know
how a negative comment on your friend's eating habits would work on
her though, different people react differently. But since your
friend is on the mend, I'd say that's a great improvement already.
Just keep going.
Sorry if my lengthy story doesn't exactly help in a direct way,
but I'd love to show some concern because it's so sad when you see
healthy and smiley friends become skinny and all sadfaced. It
really is sad.
J