Hawk, I contest! I don't know if the kids know they're "Skywalkers," but they definitely consider Nat Skywalker their dad. Obviously Micah isn't either parent's biological kid, Skeeto was adopted by both, and Anah is only biologically Droo's daughter, but that doesn't mean that Nat does not consider himself their father. I would argue that Nat's relationship with these kids is very different in terms of paternity from say, Luke's relationship with Uncle Lars. It is closer to Leia's relationship with Bail Organa. I don't think the fact that she wasn't biologically related to Bail or aware she was a Skywalker undermined her inclusion in either family. Micah even calls Nat pops. I would argue that this is indeed an example of interspecies adoption within the Skywalker family.