It is probably a mark of greatness of Babylon 5 that it could succeed so well while making so many mistakes. While Babylon 5 was famous for its arc storyline, and the fact that characters and plots were developed intricately years in advance, it was also a television show that had to deal with the logistics of the medium, and had to often explain the movement of actors by adding or deleting from the plot in a slipshod fashion. It was never going to be certain that a fifth season of Babylon 5 was going to be made, and when it was, it was moved to another network, TNT. Because of this, Claudia Christian never came back to play Susan Ivanova for another season.
And this brings us to Elizabeth Lochley, played by Traci Scoggins who was introduced in the fifth season as the captain of Babylon 5. She was in many ways a replacement for the popular Christian/Ivanova, since she was a tough chick who was hot with an attitude. Babylon 5 being what it was, she was developed as a separate character, being less dour and pessimistic than Ivanova was. The problem with Lochley's character is that the 5th season was written after the main arc of the series was concluded, and consisted of a variety of interlocking plots where her character was not actually needed as a driving force. In fact, that is another confusing (and interestingly different) thing about Babylon 5: during the fifth season, the commander of the titular station is often unseen for episodes at a time.
Some of the development that she did undergo was spotty, dependent on revelations that formed a patchwork: she was, as a teenager, a drug addict. She was, for some reason, briefly married to the former commander of the station, John Sheridan. And she fought on the side of the right wing regime during the civil war. All of these pieces look like they were adding up to something interesting, but the great denouement of the series didn't give her time, or a place, to be developed. But it is a mark of the series ethic that even though she was in many ways a replacement character, with an uncertain role in the plot of the themes of the show, that she was at least given some attempt at development. That it didn't succeed is a noble failure.