We got no support from the school, so I enriched a lot at home. I tried to avoid acceleration as much as possible, because she was too far ahead of her classmates already, and focus on enrichment instead. It’s great if they keep her challenged, but you should know that not all middle schools may be able to support her at that level, although in cases of very advanced students they may allow classes at the high school. You should also be aware that no matter what level of math your child completes, they are required by the state to enroll in a math class every year in high school. They can’t complete the math requirement early and have extra electives.
Here are some links to other threads that discuss math enrichment. Some of the enrichment options involve reading, and I don’t know what your child’s language skill level is, so you may find them more useful later. I particularly encourage you to try the links on the Hoagie’s web page, past episodes of Cyberchase that focused on math concepts, and when she’s ready for it - Scratch programming. You seem primarily interested in math enrichment, but I’m including links that discuss other types of enrichment as well.
https://www.dcurbanmom.com/jforum/posts/list/736125.page#13246585
https://www.dcurbanmom.com/jforum/posts/list/15/1126991.page#24818361
https://www.dcurbanmom.com/jforum/posts/list/917774.page
https://www.dcurbanmom.com/jforum/posts/list/15/786230.page#14585881
https://www.dcurbanmom.com/jforum/posts/list/1113430.page#24375701