Hello Virgo and welcome.
Unfortunately, codependency is just as difficult to get someone to recognize in themselves as drug abuse. I've never heard of anyone doing an intervention on a codie, though. Isn't that ironic?
If she'll listen, I would suggest alanon meetings. So often, interventions don't work. Or, they work to get the person to treatment, but the treatment doesn't work because their heart isn't in it. This can be really crushing for someone like your daughter if they don't know it's coming. I certainly understand why you are worried. However, just like you couldn't change those two alcoholic husbands, you probably can't wake your daughter up either.
With your background, do you or have you attended alanon? Do you live close enough to your daughter to invite her to accompany you to meetings?
I'm glad you joined us. Keep posting!
Hugs,
Smoke