My Mom has a UTI and has become very angry, hallucinates and has decreased mobility. How long will it take her to recover?

I want you to learn a simple dehydration test. put your hand flat on a table. Now pinch up the skin on the back of your hand. Let go. Notice how quickly it goes down? If you were slightly dehydrated, it would go down slowly. If you were badly dehydrated, it does not go back down. Very handy to know.
From now on you do that test on mom every time you see her.
She might recover in a week or two, but you stay on top of things. From now on, you ask about meds, look at test results, ask the nurse for an update, see the MD when he is coming around. There is no such thing as a dumb question. When you ask, they actually read the reports a second time, and sometimes that averts a disaster.

If there is a geriatric psychiatrist at the hospital, get her/him involved in her care. Failing that, a neurologist who specializes in dementia.

Thanks for your quick reply. She has been in the hospital for 6 days and they are treating it through her iv. And, yes, she was also dehydrated. I was just wondering if a full recovery is a reasonable assumption. Thanks.

Depends what they are giving her for antibiotics and whether the infection has become systemic. Be alert for dehydration as well. I tend to think there is more going on that just a UTI. Talk to the MD asap.