I feel the same way. I had contacted Susan Barton and asked her what I should be doing, and she said to only use the Barton system as the language arts component. Working through level 3, it seems like a great spelling system, but there has not been any grammar or extensive writing. Maybe it gets more in depth in level 4 (which I just received today), but if not, I think I need to supplement.
What level of FLL and WWE are you on? I've been trying to figure out what would be a good level for her.