We've been working well together on detail work in The Two Grenadiers and Witches' Dance is coming along nicely. We'll be starting regular lessons with her Grandma this week. For the past couple of years we've scheduled lessons only when we felt a particular need and desire, but a more regular schedule seems to feel right for all of us now. She already has such a schedule for piano lessons, so it's nothing new.
The posture issues all still need work.... the hunched shoulders, the squeezing left hand, and a somewhat wobbly, insecure bowhold. We intend to attack them in this order, since the shoulders are part of the cause of the more distal problems, and the bowhold is the least problematic of the bunch. She has made significant gains in the shoulder posture in the past month, and I have almost totally stopped reminding or correcting her on this. I'm hoping she'll notice how nice it is to play without me picking away at her posture and find this motivating when it comes time to work on the next posture task.
Now that we're doing lots of good practising on both violin and piano, I'm realizing what a big committment it is to do both instruments "properly". Sometimes more than two hours a day are spent on musical things at home, once we include the improvisation, unstructured review playing on piano, and the theory work she's doing (partly on the computer). Two instruments would certainly not work for most six-year-olds attending school, but homeschooling makes it a possibility for us.