My mom and dad had named each other as their POA’s and then my brother, me, and then my sister. My dad passed away last year and I was the one who handled everything, finances, funeral arrangements, etc. My mom is in the beginning stages of dementia and Wants me to continue taking care of finances. I am also her main caretaker. My brother and sister prefer I continue to take care of her finances (they give lots of support in so many ways) as I’m the one who has already experienced what needs to be done when she eventually leaves us. My question is, since everything is already in place, do we need to do anything to show I’m the main POA instead of my brother?
Your brother, as named as the POA now, IS the POA now, no matter what you do. HE is responsible. If he trusts you completely, and you want to do this work, continue as you are.
You are welcome to do this work if you are willing; and your brother is welcome to provide you to do this work. HOWEVER, your brother as the current POA is responsible that it is well done, and should oversee it.
If you feel you are currently doing the work for the most part, and don't wish to continue, then tell brother it's on him and hand over the records.
If you do wish to continue, then give copies to your brother of your monthly/yearly records.
If you wish to be DESIGNATED as what you truly are doing, and it's a deal breaker, then tell brother "I am currently doing the work. I would like the POA. " and he can resign. It would then pass to you. And on to your sister if something happens to you.
There's nothing wrong with doing it now just as you are. Your brother SHOULD however, since he will have been considered to have assigned you to do the record keeping, oversee it.
Make an appointment with the lawyer that did the original paperwork.
The only potential problem you may face is if your brother resists the change. He may contend that your mom does not have capacity to make the changes necessary.
If she's in the beginning stages of dementia then go with her now to an elder law attorney. This attorney will privately interview her for legal capacity and to make sure she's not being coerced. The bar for capacity is pretty low so don't make any assumptions. Her backup PoA can be your brother and sister, etc. or maybe consider a generation younger than you, if someone local, willing and competent is a good candidate.
You need to read that POA carefully. I think even if brother passed, you have to formally invoke your POA, it just does not revert to you automatically. I would have a lawyer look over the document and explain how this all works.
Beaware, that POA ends at death.