One of my friends who was a math major says that one of his college classmate was like that. He aced all the advance math courses as part of the major requirement but cannot recall simple math facts. So it is possible that your DD can indeed have gift in this area but it is not showing up right now.

Did they give you any examples on her understanding of the advanced concepts? It is one thing to not know 6*8=48. It is another thing not to know it means 6 set of 8s. Does number mean anything to her. Does she prefer to write six rather than 6?

Just trying to brainstorm here. No real experience in this area. This seems tough.