I would do like some others said and make a more simple quilt for your Mom. A family picture for one block would be really good. For one thing from experience I know that sometimes things disappear in nursing homes. So for that reason I would make a more simple quilt. Your Mom would probably love it just as much.
Wishing your Mom the best and you too!!

I would probably put a family picture or album block with the signitures of family in the center. It would make it less likely to disappear. You could also talk to the store owner to see if he/she would be willing to make an exception and cut the last block for you before March.

She already did and was told "no"