She is constantly complaining how it's all too much for her. She doesn't drive, does not attend his medical appointments (I take him to these), is unable to clean the home or even cook much, doesn't take care of her personal hygiene, refuses to take care of safety issues i.e. take away my father's car keys or remove multiple guns from the home, often is unaware of where he is or what he's doing because of her taking frequent naps. The list goes on. I feel she's incompetent and should not have POA. What does someone do in such a situation?
If not, how advanced is your Dad's dementia? The elder law attorney is the one who determines legal capacity, and that bar is pretty low. If your Dad has memory impairment, he may still pass if he can comprehend, not necessarily retain, what PoA is and does.
If this route is not possible, then conservatorship/guardianship is the only other pathway. Your Mom cannot "hand off" PoA of your Dad to you.
Also, check her PoA docs... is your Dad her PoA? If so then it is urgent that she reassign someone else who is younger.
A different pathway is to not go through an attorney but instead download the PoA docs for their home state, help them fill it out and take them to a bank or city hall to get it notarized. Make sure the PoA is "durable" (ie is in effect the minute it is signed and notarized).
Only take this route if you don't have contentious or troublesome siblings or other meddling relatives who may contest it. I'm an only child and my Mom is single and I went this route, mostly because it was way less expensive.
If you prop them up too much then they become unaware of the limits that they are overstepping in expecting you to come to the rescue. It is a stressful situation and you need to set boundaries with the amount of help and what tasks you will provide.
I have several quotes that I repeat to myself to keep my father from crossing the boundaries. "The lack of foresight does not create an emergency on my part". I will tell my father, This is how I will help and if you do not agree to that how will you resolve it on your own. It is very difficult but it must be done or my entire life would be consumed with his list at the house and medical appointments. I have a household, husband, children and myself that come first.
The second quote: I can't change the action of others but I can change my re-action. So, when my father expect an immediate response to cleaning the yard I will tell him the dates I am free for a couple of hours. That alleviates some but not all of the stress.
Having aging parents will never be easy. You are lucky that you have found this forum to help you navigate these murky waters of caregiving. Wishing you the best of luck.
You're already taking dad to appointments, do you wait in the waiting room or go in with him. You don't need POA if he will tell the doctor he wants you in the appointment with him. Doctors will often let even a close friend in an appointment if the patient asks for that. Go in with him and make sure you get all the info about prescriptions, etc. straight.
Regarding the car and firearms, POA doesn't necessarily make any of that easier. If dad is diagnosed with dementia then you head right over to your DMV, MVA, whatever and tell them. They will probably send a letter rescinding his license. Then you go ahead and tamper with the car so it won't start. Then offer to take it to be fixed, and keep making up excuses why it's not fixed yet forever.
Are dads firearms in a gun safe? Offer to get him a safe (or a new one), put them in there and don't give him the correct combo. Take all the ammo away. Go to local law enforcement and warn them he has firearms and dementia and ask what you should do. Weapons and dementia paranoia are a nasty combination.