You could continue with the plain and self-rising... but haven't you overdone that in the past? Why not go with something exotic to show you really care and gave thought to your gift. Every Mother loves flours, but make it special... perhaps a nice Rye... excellent bouqet... or better yet Whole Wheat... then she'll get the bran, the germ, and the endosperm... her heart will just rise with the recognition that you really care...
If you think I'm going into a shop and ask for flour with Germs and Sperm in it you are very much mistaken, anyway In would imagine it would be illegal to sell such items.
I have decided to give her a bunch of roses, I think two makes a bunch, and I'm sure my neighbour wont mind he has too many anyway.