Han Solo's daughter to appear in Star Wars: Episode VIII?

It is rumored that one of these actresses could be playing Han Solo's daughter. If true then who the fuck is Daisy Ridley's character playing, and why is J. J. Abrams hiding her last name? The only theory I can come up with is that she is Luke Skywalker's daughter, and not Han Solo's as many believe. If this is the case, why is she being replaced as the female lead for Episode VIII?