The simplest procedure would be for you to ask Marion herself to "draft"
the form, which would entail only her printing legibly her name and address 
and your name and address then putting check marks in the boxes with your
help. I will print out a form which you can give to Marion for that purpose.

I will also prepare a second form which will require only Marion's
signature, with my name as the individual who drafted the form, 
which you can use if you wish, if Marion is unable to print legibly.

There is no legal reason why you couldn't draft the form, but it's better
style if someone else did.

I don't understand why Marion can't sign any required documents herself. 
I don't understand why a power of attorney is required at all. 
If you would like to explain the details of what is going on,
I might be able to give you more intelligent advice.