She can find buckwheat groats in a health food store. Have her put them
in the freezer and then pulverize with a coffee grinder. The difference in packaged and freshly ground is amazing. The cold from the freezer cancels out the heat generated by the high speed grinding.
Also, I look for the "blond" version of groats, which has the dark, bitter outer skin (hull) already removed. When ground, this powder is light tan and smells like a high-class, sophisticated, upper East Side peanut butter would smell.