The pain and anger exists in every person's mind.Not what they expect from somebody they get the different result.But,the happiness is carried out the way you make others happy.Saying that a person who brings a smile to other face has hide a thousand of sad feelings in his/her heart.
first steps would be trying to talk or advising her to talk to someone trusted and if she doesn't feel comfortable ease her into healthy habits that could not only help her mental health but physical aswell