I say don't confront her. Instead, talk to her. The difference is that confrontation will make her throw up a barrier and close down all communication. Friends talk. It sounds like you have a decent rapport with this patient and a casual conversation about how she has gotten to where she is might help seek help else where.
When I transport patients with an abuse issue, after about the third or fourth trip, I usually ask them why. Sometimes they get mad and refuse to talk about it. In most cases, they want to tell you how they got addicted. When they finish their story, I take the opportunity to advise them that there are alternatives to their life style.
If you are wondering if it works, well........ Of all the times I have done this, I only know of one person that took steps to make a change.
For what its worth.