Montgomery County - have you seen this blog? http://themorechild.com/
It is by a mom of gifted kids in your county, and if you scroll down the right side, she has links to gifted resources in your county.

I think it will help to explain that you have an older child receiving differentiation and that you see your younger as more advanced. It may be that if you get the right teacher, kindergarten will be ok.

Good luck!