Would you drop the idea if your child says that she doesn't want to subject accelerate?

I have DS and DD, who are rising 4th graders, both doing some ALEKS this summer with the idea that I may want to subject accelerate DS again. DD is my "slower" twin but I discovered that she is perhaps a bit more capable that I had thought. DD is now already beyond the passing level for 6th grade math in ALEKS(you only need 85%) so she will be past 6th grade level before the end of the summer. In the fall, her 4th grade GT class will be covering 5th grade math. I can have the school assess her and move her to the 5th grade GT class to do 6th grade math. Her major/immediate objection was that she didn't want to be in that class because DS was and he knows a lot more math. However, the whole reason she is doing ALEKS this summer is because I was considering accelerating DS again because he so clearly needs further acceleration. However, that is not guaranteed to happen because it is more difficult to pursue acceleration options for DS at the elementary school when he is already at the top of the course offerings.