Way to go! That's a significant achievement.!
Now, as to your question--if she's under 35, her skin will tighten up to a certain extent. (after that, the college fibers start to break down and it's much tougher to get back to where she was.)
Otherwise, surgery (tummy tuck), lifting to have muscle to fill in where fat used to be, and loving it like it is.
I posted a link under Loose Skin Solution about a week ago which is a link to a site about skin brushing which may be of help.