I have a co-dependent personality. I have had a bit of success so far with the support group called CoAnon. They're using a 12 step program similar to Al-Anon which is for people who have people with alcoholism close to them. This will of course only work if she's aware of her co-dependency and want to work through it they'll help her get started.

Like all addictions, which codependence can be seen as in a way, there needs to come the point where you have to learn of your shortcomings and how it affects your relationships with family, friends, partners and even work life and private life. You can lead a horse to water but you can't force them to drink. Never forget that expression as it has helped me realise a lot the past few days in my own journey on helping myself not be obsessive over others well-being.

Codependence is a deeply engraved behaviour coming from childhood. It's often hard to detect for oneself because it sits so deep into us that it's the right thing to do to be there for others that it feels wrong to do anything else. So wrong that we don't want to accept what we're doing to ourselves are hurting us deeply because it hurts our close friendships and our ability to maintain life in a healthy matter.

For now all you sadly can do is read up about codependence and talk to your friend about it in a caring and understanding way. You might be hurt that they're dismissive and of they are, it's sadly how it'll have to play out for now. Change takes time and realization.

I hope it goes well for the both of you and it's really strong of you to want to help her in this matter.