My grandma was diagnosed with an UTI, decline in mental and physical abilities. Any advice?

A month ago my grandma walked up and down the stairs. Prepared her own meals, bathed etc. she has no dementia or anything. About a month ago she fell a few times. Couldn't go up and down the stairs. Had a couple of bathroom accidents. Then Tuesday told me saw evil spirits in the bathroom refused to go into her bathroom. Got her to the doctor where she was kept over night with a UTI and dehyderation. She had IV antibiotics in the hospital and been on pills for 5 days. The fast few days she has been confused,about things, hard time following a conversation, we have moved her down stairs so it has been a change in environment. We live together and she is 86. Is this normal?