GHS, it still appears that a child must be at least 5-years-old to apply.
I think the "two grades ahead" is: built into the scoring criteria if you use achievement testing to qualify for DYS; or, to give an idea of what level work should be contained if you choose to complete a portfolio with your application. Also, I think that it would give "context" to your application if you share that your DD is working grades ahead.
I have two DYS. Neither is grade skipped, but they are both relatively young for grade. We are currently trying to work with our local P.S. DD9 is in G&T/advanced classes, but is showing signs of possibly needing acceleration/or greater differentiation. Meanwhile, DS6's teacher is currently attempting differentiation, because G&T programming does not begin until 3rd grade. When I look at the school options available to us, I see no "perfect fit." Also, their needs seem to constantly change, so flexibility is key!
If your school is meeting your DD's needs - that is WONDERFUL! You'll have to decide whether testing is useful to you. Our DC face testing for the G&T program in their current school, anyway. Testing DS a bit earlier simply allowed us to be more certain of our direction and the need for "something different" sooner, rather than later.
We are still somewhat new to DYS, so I think that others can tell you more about the benefits they have had through the years. I have already learned a great deal from the other parents.
