I don't have experience with the Alex Math. I have looked at the program briefly and we are going to do the free trial.
My thoughts are she does not need to do Alex if you don't want her to accellorate quicker. I would suggest she only does the Alex fact practice for addition, subtraction, multiplication, division. I think we could all do well to increase our calculation speed and accuracy.
If you want to give her more math to do at home try something more like math puzzles or Math logic.
See mindware.com for work book ideas, you can print out sample pages
Also people here have used Murderous Math series books.
here are some website with Math, The 1st one I have not tried yet but looks interesting.
http://nrich.maths.org/public/viewer.php?obj_id=2710http://www.freerice.com/subjects.phphttp://resources.oswego.org/games/mathmagician/maths1.htmlBest of luck