LastOneStanding, she has the right to live her life as an addict. Your father has the right to choose his relationship with her just as you have the right to choose your relationship with them.
The 3 c's applies to codies as much as it does to addicts.
I didn't cause it.
I can't control it.
I can't cure it.
You can no more manage his codependent behavior than you can manage her addiction. I know speaking as a recovering codie, only I have the means to work a recovery for my compulsive behavior. There was nothing anyone could say or do to get me to give it up until I was ready to do so.
Your friend,