My mom's dementia keeps her from understanding she needs to sign the forms the tax preparer mailed her. Any suggestions?

does she actually say "no"? or does she say "I'll do it later" ?
sometimes when I need to have my mom sign. I have her practice on a separate paper so she feels more comfortable (since she no longer signs her name a lot, she almost forgets how) Also my mom get overly concerned with how "neat" her handwriting is. Just a thought, if she could do a simple "X" if you could check with the CPA if that's allowed. Sometimes doing an enjoyable activity together to make her mood happy then I can get my mom to co-operate better. Once they get annoyed with a request its like they shut down a little. You might try saying, if you do "this"...then later we can do that. (maybe a special trip to the store) sorry first time posting here not sure if any help.

For years, she has used a "signature stamp" her bank made, from her authentic signature; her hand shakes when she writes. Uses it everywhere that requires a signature; nobody has objected. Besides, she tends to give me a lot of glib and irrelevant talk instead of signing the form; she reads things into papers that aren't there.

How about taking out the stamp and saying "mom, would you like to use the stamp, or shall I? We need to get your tax returns to Mr. X today"? 

In other words, you give her a "forced choice--this or that. She can stamp them or you will do it for her, which would you like mom? 

Not "would you like to sign the tax forms?".

Let the POA sign. I don't think my Mom would have ever followed a request for her to sign something. Can't you just sign it?

I have not as yet been able to achieve Power of Attorney. Long story. Today I intend to tell her that if she just uses the stamp on the forms I will personally take the forms to the preparer's office, rather than mailing them.

Denouement: I had been in contact with my sister by text messages. I told our Mom one of her messages: The IRS could sue her. She relented and agreed to sign the papers as long as I would have her go with me back to the tax preparer's office. So we went; Mom signed the papers there...hey, I just wanted to get her to sign the papers, whatever it takes, within reason.

If you have POA you can sign it. Sign your name with POA after your name. I do this with my nephew. Check with ur preparer.