The homeschool co-op crochet class ended yesterday. My daughter K wound up joining it in the middle, and has learned to chain, slip and single crochet.
She has no interest in following patterns at the moment (well, reading hasn’t kicked in yet anyway, so that makes sense), but she is making up her own shapes, experimenting, and deciding what to do with the pieces later.
We have only two problems: she has used up all my spare stash, and she is leaving snips of yarn all over the house. 
But she now answers herself, “I can crochet!” whenever she declares, “I’m bored, what can I do?”
The other little girls have learned granny squares, wiggly worm bookmarks, or how to noodle around with a hook as they pleased. One is reading The Big Book of Little Anigurumi from the library and has learned to follow the patterns.