Unexpected caregiver, any advice?

Stop trying to convince your aunt of anything. She’s not deaf but her brain doesn’t absorb what she hears. She’s not blind but her brain doesn’t absorb what she sees. The best you can hope for is that she forgets even more about her loss of home and loved ones or that you can learn to distract her with something she can still relate to.
Aunt. I want to go home.
You. We will go when the doctor releases you, look at these adorable kitties on my phone. Aren’t they sweet?

Do not continue to try to convince her of anything. It is stressful to you both. She can not take it in.
About the taxes. So great you have last yrs taxes as a guide. Turn it all over to a CPA.
Good luck today.

CountryMouse, when the aids in my MIL's LTCF were getting resistance from her to get out of bed and join others in activities (because she was perfectly able and it is good for her) my husband (her son) wrote up a sign that said, "Mom, the doctor says you have to get out of bed to eat your meals. Love, Bruce" and the aids would point to it when she resisted. Because the note was signed by her son (and she still recognized his signature) she has worked up to this point. I'm sure there'll come a time when that tactic stops working but for now it was a clever and easy "fix" and the staff really appreciated it.

My mind is boggling.

You put up a huge visual aide stating that your aunt is now in her new home?

What on earth does it say?

She has dementia. That’s why she needs you to take care of her. Trying to give her broken brain new information will probably not work. It will also be frustrating that she may SEEM to comprehend what you are telling her, but then either not recall what you have said, or be able to hold on to what she’s been told, nor be able to use it.

I totally understand the terrors. One thing I find useful is to consolidate assets as much as possible, and do all of her financial transactions from the consolidated account. Good for record keeping for taxes and insurance purposes, and simpler for whoever writes the checks.

She will gradually adjust to her surroundings, and the time frame for that to happen will be hard to determine.

If she is hostile or unpleasant to you, try hard to not be offended. Also with time, you will adjust to the fact that she isn’t the woman whom you knew in time past. Accepting her as who she is now will be easier for both of you.
I can literally communicate with my LO and respond to the same comment 20 times in 10 minutes as though each of the times was the first.

If she’s oppositional, try to let her comments go. There is nothing in it for either of you to attempt to correct her or try to change her mind. Distract, change the subject, defer.

Learn to love her in her new self. So tough to do but again, good for you both.

As the saying goes, you’ve joined a club that no one wants to join.
Remember too, that you will often be making decisions on her behalf in which there are NO GOOD SOLUTIONS. You will be required to make the best choice among all the bad ones. Do that without guilt.

Let us know how things are panning out for her and for you. Someone who’s willing to listen is always around when you come here!

This is just me, but when I go for even a little help, I find that I am running around more to get the info people need to be of help.

Glad's idea of a CPA is a good one. Because I feel they still work for you, specialize in facts, whereas most attorneys will take over a case, on their timeline, and you have to pay for their time to be updated. Not always a relief.

So, I personally have survived by having a few trusted friends who share info with me, and many caring people on AC even when advising others, I learn from them.

As for filing taxes, if no money is expected to be owed, take advantage of the extensions to file. That's all I got. I could be wrong, some could misinterpret my advice, some will disagree with whatever I say. I am not an expert at anything.

Here are some little tidbits I use to console myself:

1) What can be done by paper, can be undone by more paper.
i.e.: If you file the facts wrong, you can later get help to file an amended tax return.

2) No good deed goes unpunished.
i.e., if you expect this strange occurrence, it amazes you less.

If the financial work is what is very difficult and time consuming maybe a CPA would be all you need and save some money.

It is always good to have an elder law attorney on board for those tough legal questions.

This is indeed a very hard job. Even more so alone. Support is a necessity.
As for explaining, unfortunately, with dementia, they are too impaired to understand or remember things. It takes a lot of patience.
All the best, take care