I would base my decision on whether your daughter wants to subject accelerate. However, I also would give some weight to the school's rationale for offering the acceleration as well only if neither you nor your DH ever complained and/or pushed for acceleration initially.
You also need specific information on how this acceleration will be implemented and all the practical details on how it will impact her schedule day-to-day and during special occasions.
Not choosing to accelerate is not crazy. I made that decision for DD in 4th grade (not choosing Pre-Algebra for 5th) because she did not want to accelerate partly for social reasons. It had nothing to do with her academic ability. Acceleration required other sacrifices - inconvenient scheduling and occasionally missing certain activities and the general stress of being out of sync. It also meant being stuck with a couple of "nerdy" boys for math instead of hanging with her friends. While DD has been bored/annoyed with the slow pace of Pre-Algebra in 6th and Algebra in 7th, she has consistently appreciated being grouped with her friends and is fine with Calculus AB Junior year (current path) rather than Sophomore year had she been accelerated. This also made sense for DD because her strengths/passions are in the areas of visual arts and language arts.
On the other hand, I chose to accelerate DS in 2nd grade (to GT 3rd grade, which was combined 3rd/4th grade math) and again in 4th grade (from 6th to Pre-Algebra) because he really wanted to acclerate. Those accelerations were still considerably below his actual math ability levels at the time so it was pretty stress-free while he focused on developing his writing, graphing calculator (Pre-Algebra & Algebra) , typing/computer (various software programs that he needed to learn independently for Algebra in 5th) and executive function abilities. While the school made efforts (2nd grade teacher switched her math block to the mornings to match the 3rd grade schedule), there were inevitable mismatches/snafus (class field trips, state testing, etc.) so it made all the difference that DS himself drove these accelerations. For this same DS, I also chose not to pursue acceleration in K or 1st grade because he did not have the requisite writing or executive function skills in place. I also chose not to accelerate DS to Algebra I in 4th grade partly because we (including DS) wanted to make sure that his foundation was the strongest possible and also with an eye toward middle and high school considerations.
Keep in mind that those were not the only or even necessarily the best possible decisions but they were reasoned decisions at the time and nobody is tearing their hair out in hindsight.
I think that math acceleration in early-mid elementary can be a tricky decision for both student/parent as well as the school district partly because you can't always tell whether the child who excels at elementary math will necessarily find Algebra "easy" at an earlier age as well. I would say that as long as you can reverse an acceleration without damage, then it may be worth a try as long as your DD is not opposed. Good luck.
Last edited by Quantum2003; 06/04/16 10:45 AM.