Involuntary Rehab?

I have a member of my family that has a drug problem and either doesn’t know it or refuses to acknowledge it. Normally I let people do their own thing but she has a 3 year old daughter and although I know there is no imminent danger, it kills me to see someone I grew up with as kids slowly turning into an empty shell of a person, and I also worry about long term effects to her body and mind. So what needs to be done to “commit” (so to speak) her to rehab against her will? She is an adult and lives in her own home with her boyfriend. I’m looking for an intervention without all the TV bullshit. Nobody needs to know our lives, I just want her daughter to have a mother, not just a mom.