But a subject acceleration would be great.
Your DD is a first grader, right? FWIW, my DD's first grade teacher told me that the typical reading range she sees in a class is pre-K to 7th grade, so your DD's class may have other kids who are reading at about the same level.
One thing to consider with subject acceleration is that the volume of written work increases as grade increases, and a 6yo may struggle with 3rd grade writing expectations. (My 8yo had a hard time adjusting to 4th grade writing expectations.)
And a one or two grade subject acceleration won't necessarily mean she's reading challenging material - and if she starts with a placement that gives her challenging material, it won't necessarily be challenging a few months later. We use STAR for reading assessment, and my DD went up 4 grade equivalents in 4 months, for instance.
