In his book, "Why Don't Students Like School", Daniel T. Willilngham details some of the recent cognitive research on learning. One of the most important results of this research in terms of teaching math to young students (third grade and below, I would say), is that new, synthesized knowledge in human brains is created from basic, memorized facts. This kind of research leads many (including myself) to the conclusion that students should memorize their times tables as soon as they are ready to. One of the reasons I'm a "math person" today is that my third grade teacher drilled us in our times tables, making it a kind of game where we tried to answer a sheet of one-digit multiplcation questions as quickly as possible. This made it much easier for us to do simple division, long division, and reduce fractions, all of which are essential starting in second and third grade.
You might also check out "Secrets of Mental Math" by Arthur Benjanmin. I've discovered that learning tricks to make mental math easier is something kids really enjoy and of course it gives them a lot more power and comfort when learning more advanced topics.
Finally, you can do no better than to get her a talented and experienced tutor, if you can afford it.