Their relationship didn't get really interesting until Deep Space Nine, where Miles was reassigned to a space station that Kieko hated and didn't want to live. Adventurly Kieko fits into station life as the station's school teacher, until several years later when the civilian population of DS9 demishes severaly and there is no longeer a need for a school teacher. We see how Miles agonizes over the fact that Kieko is no longer happy, so he gets her a job as head botonist on an expidition to Bajor. So from then on, Kieko and Molly travel back in forth from Bajor to the station.
Their relationship has improved as the series went on, to be intresting and productive to the series.