Our son, recently seven and in first grade, has to do math tests at his school that sound similar to your DD's. They start with addition and move through multiplication and then division...all at the child's pace. The tests are all timed.
We asked for copies of the tests. Each week, depending upon which test is coming up, we copy sheets and challenge him to do the test. We then go over the problems he doesn't know. Basically, we "teach to the test".
Also, we have DVD's of math that he watches. For instance, we have the DVD of
Schoolhouse Rock Multiplication. It makes memorization a bit more fun. (Sevens start at 16:50)
Our DS is in third grade math and recently passed a 78 question, five minute timed test in all division facts up to multiples of twelve.
He had difficulty with seven's, too. Tell your DD not to give up!