OP, while she’s in the hospital, ask for social work services to help with discharge planning. Then go visit the sites to see what you think, what services they offer, and what the atmosphere is like.

A family that I’m close to has had very good experiences at Arden Court in Kensington. I don’t know if they offer Rehab though.
Brighton Gardens facilities offer Memory Care and Rehab, but each facility is different,
JCA - offers help with accessing appropriate services and might be able to assist you with finding appropriate resources.

I know that this is both difficult and frightening for both you and your Mom. Please try to think of this as a temporary crisis — at least for now.

OP, I'm sorry. My mom has this after tramautic injury hip replacement, this past summer. It started 48 hrs after surgery and lasted about a day. My poor mom was so terrified! She thought 'they' were going to kidnap me and my young dd and she called the police!!! Thankfully they always call the desk of the rehab when they get calls from there, just for this reason...

The nurses recommended she hydrate-apparently fluids help carry the anesthesia out of the system. After a day in rehab, she was much better mentally. I'd push fluids to your mom-have her drink drink drink- and help her get into the rehab's place routine. I think she will improve.