Very MUCH so!

I think you're doing her a great favor by eliminating as much refined sugar and junk as possible. Kids do better behaviorally, socially, and in a lot of other ways besides just being all-around healthier without it.

I'm not a hardcore about it, but I do find everyone's happier without the extra sugar. My son grumbles(he's 13, it's his job!), but he still gets his treats, albeit mostly of the lower-sugar variety. He can't tell the difference between regular ice cream and no-sugar-added frozen yogurt, for example. To him, it's all good.