My DD8 is DYS and my DS11 is not. DS is 2e and very bright, 4 points from DYS level on PRI but his achievement scores are significantly below IQ because of ADHD/dysgraphia. DD is a kid who is "wired for school", off the charts VCI and very high WMI as well. (Funny, because my DD's PRI and my DS' VCI are exactly the same. They are almost mirror images of each other in IQ.)
It's tough because DS has struggled so with school and DD sails through with perfect grades and no effort. DS has complained and actually thrown fits many times about the "unfairness" of his school experience versus hers way before DYS came along.
I would guess that your kids have figured out who is "smartest" and "best at school" without DYS. I think kids are much better off if they are parented consistently but with an accounting for the differences between them, not treated exactly the same. A "B" on a spelling test is fabulous work for DS and NOT representative of DD's best effort and that same grade meets with a different response.
Personally I would never deny my DD the help and support we get from DYS just because DS can't also be in it. My DH and I have only casually mentioned DYS around the kids so it's not much of a factor, but believe me your kids have probably already figured out that they are different and how. That's ok, as Grinity points out, IQ just a number that represents a part of who you are. The real tragedy would be if they weren't all distinctly different and wonderful in their own surprising ways.
