Anonymous wrote:OP here--thanks all! I guess I was thinking that with a legally free kid from out of state (as opposed to a kid who's already in a DC school) if we happened to get matched but not placed during the lottery time it would make sense to enter the lottery based on what we know of the kid; if the placement didn't happen we could yield any spot we got, and if it turns out the kid would be a better fit at the in-bound school we could always change to that (except in the very unlikely scenario that the kid was in PK).
Certainly if the kid was already in a DC school and/or didn't have parental rights terminated, things would be very different.
I don't have experience with it but know a family that fostered and then adopted children. My understanding is that foster kids are considered "at risk" and there are a number of seats at each public and public charter school set aside for their placement. I recall that my friends chose a nearby DCPS and then later moved to a charter for a better fit.
You'll definitely get more details on that once you're in the foster system, but don't enter the lottery before the child is placed in your home. Good work and good luck!