When you have a highly gifted child in math, be prepared for a lot of frustrations. We go through each year looking for the "least worst" school options. I would highly encourage out of grade level testing to see how your DD tests in higher grade level academics.
Based on your post, there are several issues that I would like to provide some insight. I am not an expert, but my DYS DD11 has some similarities to your daughter. She excels in math and has a full grade skip, and as of last year had a double grade skip in math. Her vocabulary and implied comprehension are the areas of relative weakness.
My DD's processing speed has always been fast, and as a result we see her make a lot of careless mistakes. Her working memory is high, and she manipulates a lot of things in her head and skips a lot of different steps (especially in math).
We have tried many different things, but here are some strategies that worked best.
1. Because she was so far ahead in math, most teachers did not work with her very much, and as a result, there were a few building blocks missing from my daughter's math, and they were never discovered or resolved in school. Keep in mind that the computer math programs are a good tool, but not necessarily the best for all learning styles. My DD has not used Project M3 or Ten Marks, so I can’t comment on those specific programs. My DD’s school used ALEKS last year, which was a fill in the answer (not multiple choice answers). It did not include much repetition, and moved through topics rather quickly. There were typically about 500 topics per grade. What we ended up doing was paying a high school math tutor to go in and work with her one-on-one for the topics not mastered toward the end of the year in math in order to fill in any gaps. That one-on-one instruction resulted in a huge progression in her learning. What we found is that there were a few learning gaps, but once discovered and explained, she would zoom ahead until she hit the next road block.
2. With regard to the reading comprehension, there were some glitches with implied comprehension simply because my DD thinks differently than the general population. We ended up with one very good ELA teacher, who took the time to spend with DD on the questions she struggled with (along with the thought process that it took to get the questions right). A lot of the questions in upper grades start getting more obscure, so with the poor wording and vague references, it becomes more of a skill to get answers correct. (Comprehension can also creep into math if your DD is not able to ascertain what the question is asking.)
3. Does the school teach vocabulary in school? What we found was that vocabulary and spelling were kicked to the curb, and our DD had some huge gaps when it came to vocabulary. We ended up using a lot of Vocabulary.com to help build her vocabulary words, and as a result, we have seen a lot better performance since we have incorporated.
4. With regard to processing speed, my DD will zoom through assignments quickly. Careless mistakes occur because of this, so what we do is have her go back and read the questions, and make sure that she ANSWERS the question asked. In Math, she does better when she uses the CUBES methodology on word problems (Circle, Underline, Bracket, Eliminate, and Solve).
Please feel free to PM me if you want more specifics. It has definitely been an interesting journey. Good luck with your DD!