I have a customer who wants a coach purse design.  I was planning on using fondant accents. But then she said she wanted less sugar in the frosting because she is diabetic. Does anyone have any good diabetic frosting recipes that would work well with fondant?

Here is a diabetic "buttercream" recipe. It really sounds awful, but it might be worth sacrificing some ingredients to give it a try. If it tastes good to you, you might want to ask the customer to taste it as well just to be sure she likes it. 

http://www.justapinch.com/recipes/dessert/other-dessert/diabetic-friendly-butter-cream-frosting.html

Also, you could do a Swiss meringue buttercream. There is only 1 cup of granulated and 1 cup of powdered sugar in the whole recipe. More butter and eggs than anything else.