How do I find a reputable geriatric physician in the Antelope Valley, CA?

My Roommate was admitted to the hospital after going through a crisis with a long term addiction to prescribed pain meds. She had reached the point of a complete mental and physical breakdown. The admitting physicians diagnosed her with hyperthyroidism. After a month in the hospital with total mental and physical collapse, expecting her to die any day, the treating physician and psychiatrist decided to transfer her to a SNF to either recover or die? She was diagnosed as being bipolar/manic depressive, dementia, and hyperthyroidism. After a month in the SNF, from not being able to sit up, much less walk, she can now walk better than she has in months. She is able to think, reason, and relate better than in months. I personally believe she does have some dementia because of her difficulty reading and following directions, some memory difficulty but not enough to justify leaving her in a home for Alzheimer/dementia patients. I need a reputable physician who knows about aging and treatment for the elderly for long term to re-evaluate her so I can bring her home. Any guidance and/or advice would be greatly appreciated. I need to do something as quickly as possible since she is suffering greatly in that environment and I am the DPOA who is responsible for her safety.