It's a touchy subject, a lot of these girls are independent women and don't like to be told what to do.
If you really feel the need to mention something to her but if she doesn't want to have the conversation, let her be. She will have to quit on her own turns and when she wants.
I have never faced that addiction but I've dealt with SPs that have but as a client, I don't feel it's my place to lecture them, unless you have that close enough relationship with her already.