Sandy
I'm not sure how old your Mom is but, dealing with everything she has been in the past year is bound to make her "cranky". My Dad was the same way as he got older. Just like DM's Mom..had to have structure and no deviations from it!!
Also, the fear of the unknown is probably alot of it. I know it's hard. I used to just bite my tongue when he'd start in with his list of negativities.
I hope everything works out for her and goes smoothly. She (as well as you) deserves a break.