It's worth a try. The whole idea is to use whatever memory trails are most efficient for encoding and retrieval of math facts. She understands arithmetic operations, I assume, just can't reach automaticity (if I recall, this is across the board--she had difficulty with reading fluency, as well, didn't she?) easily. There are also a variety of math fact musical products that other homeschoolers I know swear by. I can't remember the names of any of them off the top of my head, but I could find out. Or you could just search youtube.
