You can call 911 and an officer or EMT will come out. If she is able to refuse treatment verbally then they will not be able to take her involuntarily to the hospital unless they think she has overdosed. Maybe she is mixing her drugs/alcohol and you could mention that when you call?
I'm a police officer in Texas but each state has differnt laws. I can take a person who is a threat to themselves...or others. So, basically she has to have said she was trying to commit suicide or taken an action that could kill herself. Same with the paramedics.
If you bring her to the ER they can take her blood levels and make sure she is alright but she will probably just be released after a few hours of detoxing. They may referr her to some treatment centers but it would be her choice.
This is all assuming she is an adult...over 17 here in Texas. If she's a juvenile you can take her to a facility and admit her.
Best of luck.