Ro Laren was wanted on another space ship
Michelle Forbes was a popular actress when she played Ensign Ro Laren on Star Trek: The Next Generation. And producers for Star Trek: Deep Space Nine had the idea to make her the First Officer on the space station. Forbes didn’t want to be a series regular, though, so that idea was quashed. But the entire idea for her defecting to the Maquis was actually set up for another reason that had nothing to do with Deep Space Nine.
According to What Culture, Ensign Ro’s betrayal of Captain Picard was specifically written to set her up for a role on Star Trek: Voyager where she would fit right in with the other Maquis soldiers on the run from Starfleet.
Ensign Ro Laren wasn’t going to be a regular character
When Voyager was in pre-production, the team suggested that Laren could be one of the Maquis renegades that Voyager was trying to track down. During the events of the first episode of the series, the idea was to either have Laren be killed shortly after the Caretaker sent everyone to the Delta Quadrant or taken away from Voyager for some unknown reason so she could return on an as-needed basis.
Of course, Laren never made it to Voyager, and all but a handful of the Maquis were killed, and those that had survived were sent to prison. Knowing the way her character was portrayed, though, Laren was undoubtedly one of the survivors who was never taken captive. It would have been interesting to see how she interacted with Captain Janeway if she had been aboard Voyager. That would have been a clash worth seeing as I can’t imagine Laren would have meekly agreed to serve aboard the ship after she’d already turned her back on Captain Picard and the Enterprise crew. Odds are good she’d have spent a lot of time in Voyager’s brig.