Sort of... Karla worked with Doug Griffin at Way-FM as "Doug & Karla". She left and was replaced by Marcia Ware. "Marcia and Doug" were paired together for a few years, and then Doug Griffin left and was replaced by Doug Hannah. So, the show remained "Marcia & Doug", although the Doug had changed. It was practically a Dick York/Dick Sargent thing.
Doug Griffin is the Doug who went to The Fish (Doug Hannah is now at Mix 92.9 and SiriusXM), and hosted with Kim Bindel for several years ("Doug and Kim") before Kim left for maternity and Jaci Velasquez permanently took her place.
I may have one of the details wrong, but I don't believe Karla Lawson ever worked at The Fish. If I remember correctly, she went from Way-FM to Metro Networks (traffic) and then to Clear Channel, where she did traffic for The House Foundation for several years, before being paired with Billy upon Gerry's retirement.