She lives alone in Montana and I want to care for her in California. Her payee says it would be difficult to change payees, that I should send her invoices and she would mail checks. We don't have a lot of expenses so her rent here would easily be 1/3 of our bills. I'm not exactly sure how to figure the rent amount or her personal spending so where do I go to find out how to be a payee and is it all that difficult?
Being Rep Payee involves going to Social Security and providing to them documentation that the person cannot act for themselves in any way and therefore needs someone managing all the finances. It would likely involve your being also financial POA.
This all has a very steep learning curve and because you are dealing with government and banks they are going to be ON YOU about everything. This isn't something that you can manage without a lot of thought and knowledge. You might start by going to Montana and learning exactly what the Rep Payee does there for the cousin, and then go together to an appointment at the Social Security office to discuss.
A move this monumental? I see troubled waters a plenty ahead in every wise. I was POA and Trustee for my brother when he was well, still, but was newly diagnosed with probable early Lewy's Dementia. Even as well, as organized, and as cooperative as he was it was a JOB, and I did find the learning curve steep indeed.