Ask a Psychiatrist and Get Answers to Mental Health Questions ASAP
You can talk to her treatment team to try to get her released, but legally they can hold her for observation for up to 72 hours to assess her level of dangerousness to self (or others, but that doesn't seem to apply here). While you may not be able to convince them to release her prior to this time line, your input will most definitely help them decide whether or not they will need to keep her there longer. I would suggest that you be very pro-active in outlining (with specifics) why being at home with you will help her stay safe, who will be there with her when she comes home and who will be her emergency support system (as many people as possible, and specific names), and what kind of outpatient follow-up care she will have (this usually consists of a psychologist for psychotherapy and a psychiatrist for medication management). If you have all of these things in place and can show the treatment team at the hospital that you are confident in your wife's safety at home they will likely release her after the 72 hours. In the meantime, you can talk to your wife as regularly as possible during her stay there and consistently reassure her that you are doing everything you can to get her out and to keep her safe.