There is a brand new building on the north end of SS that would put you in the Woodlin ES district, which seems to be very well liked. The middle school, Sligo, not so much, but you have very young kids and I'm presuming you're not necessarily looking to stay in the same apartment for many years, so the middle schools may not be a concern.
The building is:
http://premierapt.com/
But as the PP noted with regard to Sligo Creek ES, though the apartment may be very Metro accessible, the school is not, so you would still need to use a car for pick ups.
Good luck with your search!