I previously posted a spinach dip recipe that can be made low-fat by using non-fat sour cream and low-fat mayo:

http://www.recipelink.com/msgbrd/board_14/2000/JAN/4314.html

I've found that with almost any highly seasoned dip, you can substitute low/non-fat sour cream and mayo, and no one can tell the difference.

Best wishes to your family!