[OMFG!You'reActuallySmart!]

There is involuntary admission which can be done but since she is an adult (i.e. over 18), the only way for her to get treatment by this would be if she comes home and then gets admitted or the people she's living with admit her. When involuntary admitted, there is also involuntary treatment but I'm only familiar with how it works in Canada, as far as I know it is in the US and I think follows similar policies.

If she hasn't been diagnosed, she may not be bipolar because although her father has it, that only increases her chances but will not ever be a 100% definite she will get it. Even if her mother also had bipolar, would not be a 100% definite. So whatever her diagnosis is, it may not be bipolar or may be additional disorders.

In Canada, she can get to the hospital either by herself, by ambulance, by police, by family or by others, I'm sure it's the same for the US.