I have not found the patience to teach my then 7 year old to knit; she just couldn't get it. However, I found teaching her to crochet much easier; she picked it up very quickly. Now she is knitting with "Knifty Knitters". I figure she'll work with these for a while, then go on to knitting with needles.
I think with crocheting, there is simply one less thing to have to hold onto and manage. With the knifty knitters, since it is a loom sort of thing, it is easy for the child to hold, and it really does make some neat projects.
As I get better at knitting, I think I will be better able to help her learn to knit. When I was teaching her before, I wasn't so great at it myself, and I think I was frustrated with both of us. Now that she has a little more hand dexterity, and I have a little more experience, I'm interested in trying again. I also think I need to pick a time that I am not in the middle of four different projects. The first time I tried to teach her to knit, it was right before Christmas, when I was trying to get all of my last minute projects done. Maybe right *after* the holidays is a better time!