Yeah, that's an interesting point: is this film the end-point of Star Wars - that is to say, will any new films and tv-shows cover the time post-IX? Or are they doing a Mass Effect ending with no hyperspace and/or no Force anymore ... I doubt that, no money in dead universes ... to paraphrase.
I'll probably regret this, but I doubt she's a Skywalker - as in blood relation. But she could be a "Skywalker", as in created by the Force.