"How valuable NBC Magazine was in my career is questionable"

Jessica Savitch's quote suggests that the value of NBC Magazine in her profession is uncertain. This might imply that she is unsure of just how much the magazine contributed to her success, or that she is uncertain if it was worth the effort she put into it. It could also suggest that she is questioning the effect the magazine had on her profession, or that she is not exactly sure if it was helpful to her in the long run. It is possible that she is reflecting on her profession and the function NBC Magazine played in it, and is uncertain of the effect it had. Whatever the case, it is clear that Jessica Savitch is uncertain of the worth of NBC Magazine in her profession.