^ Not (re)using characters has nothing to do with continuty.
It does when it makes logical sense for a character to appear and then they don't because they writers thought they killed them off, but really didn't.
Why was Naomi Wildman spending all her time with 7 of 9 or Neelix, rather then her own mother? Why wasn't Samantha Wildman spending any time with Naomi? Was she just a bad mother or something. Its not good story telling to have a mother and daughter on a show and then just have the mother disappear with no explanation, but keep the daughter around, it begs a lot of questions.