How do you enroll a 27 year old into a mental institution?

Placement question: One can no longer "commit" someone to a mental institution because s/he is mentaly ill. There are different types of treatment facilties available for mental iillness: emergency room eval, inpatient psychiatry ward then eval for other placement, incl: temporary locked facility, residential/unlocked placement, board and care or other as indicated. Please seek professional evaluation!

2 ways: Since she is 27, the primary way is that she has to want to go for treatment - that's easy. But, if she refuses, then there has to be some indication, concern, or history of potential harm to herself or others. In that case, she can be committed by any individual (related or not) who files the proper document with the state. In florida, it's called the baker act.

Depends : On why and which state you are in. Most states allow for emergency evaluation of a person that is suicidal, homicidal, or unable to care for his/ her self. Admission can be offered voluntarily or involuntarily, depending on the determination of the evaluation.