You should remember that the whole thing is a work in progress (and it would be true if you were HSing as well).
I agree that you should let your daughter settle in, but keep a keen eye on the work level. One thing that is nice with the 1/2 classroom is that she will have friends in 2nd grade that she can move on with. That would give her a 2 year acceleration, and then you could work with the school for additional subject acceleration. Every kid is different, but that seems to have worked pretty well for several PG kids here and others I have met locally. The fact the principal even appears supportive is a good thing.
