Basically anyone can involluntarily commit anyone. to do this if they are not the persons legal guardian they have to either go to court and prove the person is unable to mentally and physically capable of making their own medical decisions. you will need documentation that she is unable to maintain a checking account, pay her own bills, do her own shopping and make her own meals, take care of her own home. Once guardianship is granted all you have to do is request the court to involluntarily commit her until you can find a suitable long term facility for her.

If not going the court route anyone can take anyone to their local ER and request the person be seen by 2 staff psychiatrists for possible involluntary commitment on the grounds of being a danger to herself and or others.

she will be seen by 2 psychiatrists that will decide if she should be committed or released.

Beware though you go either route and she is deamed mentaly competent and not committed she is going to be royally mad at you. If you are living with her you might want to find another place to stay before taking action because after taking action you will probably not be welcome for some time in her home.

Once she is in the Mental health Unit like already stated she could sabotoge the plans or play a game of "I'm getting better thank you so much for your help" just to get released.

It is better if someone of authority - her doctor or the police - do the committing and that she wants to go. otherwise you will be on the recieving end of the fall out from your committing her and she will not do the program.