If she is currently 9 in 4th grade, was she on the older end for grade pre-skip? Both of my girls started 4th shortly before their 9th bds b/c they had those bds that put them on the younger end. My oldest also skipped 5th.
I mention this b/c it sounds like the one skip wasn't enough for your dd and, if she was on the older end for grade, that wouldn't be surprising given how able she is. Have you considered having her skip another grade or at least pursued subject acceleration?
Given that she's rather advanced in both LA and Math, I'd be kind of leaning toward considering another grade skip over subject acceleration b/c it sounds like she'd need to subject accelerate in multiple subjects anyway.
In re to curriculum compacting, that would enable her to do two years of a subject in one year. I've honestly never seen a school offer it for just one student or a small group, though. What I've seen happen is a school offer, say, a 5th grade math class that compacts the 5th & 6th grade curriculum into one year if they have a lot of students who can handle that pace. Those students would then go on to take 7th grade math the next year.
