You guys just reminded me how awkward it's going to be for a Dunmer couple and their adopted Nord daughter...
Can't be any more awkward than it was for the parents of http://www.uesp.net/wiki/Skyrim:Brand-Shei, a Dunmer raised by an Argonian family. Nords have actually helped the Dunmer quite a bit, all things considered, by allowing them to stay as refugees in Skyrim. Argonians, on the other hand, decided the eruption was the perfect opportunity for an invasion.
Anyway, why would the race of your adopted child in a fictional universe matter much at all? I would certainly hope it wouldn't if the situation arose in real life. "Ugh, time to find another orphanage, they only have [race] kids at this one".