Episode S04E06 of Doctor Who -- titled "The Doctor's Daughter" -- is about a war between two species. During the episode, the Doctor forcefully became the father of a girl named Jenny. Jenny died in the end. The Doctor thought that she could not regenerate and left her to her people. In the end scene, we see that Jenny can indeed regenerate (at least some sort of regeneration; she didn't change in appearance). She stole a shuttle and flew away to experience adventures. Jenny was never mentioned again the series.
Is there a comic, side show or audiobook about Jenny, or was it just a hint in a story arc which was never really explored outside of that one episode?