Jenni I don't know how much you've read around the site, but one of the things I learned here when I first started reading was that "High-Functioning" is not a type of alcoholism, it's a stage. The disease is progressive. How the alcoholic is today, if they do not choose to seek recovery, is the best they will ever be.
The good news is, you are here, you found this place, and you want to know more. If you look through the "Sticky" posts at the top of the Friends and Family of Alcoholics forum page, you will find a wealth of experience, strength, and hope as you learn more about what you are dealing with.
This community is here to support you as you decide how you want to live the rest of your life. Please keep posting, and welcome.