I do recall she got a shot at Vader in Splinter of the Mind’s Eye but I don’t remember if it was handled well.
Splinter is generally a strange artifact of the pre-ESB expanded universe. It’s very entrenched in a ‘70s kind of sci-fi writing and none of the core stuff ESB established is anywhere near Foster’s mind. It also has Vader’s defeat coming from him tripping over his own severed arm, so that’s kind of a weird moment.