That being said, my affection for the character grew in leaps and bounds once she was no longer an official companion traveling through time and space every episode. I squeed with joy when she appeared in a few episodes of Torchwood. I loved her roles in Series 4 of Doctor Who and even fell quite in love with her when she teared up and said "Oh my god, he found you," upon meeting Rose Tyler. Outside of the TARDIS, Martha is not only Brilliant, she's triumphant.
One of the things that really helped her transition (or the fans' perception of her transition) out of the TARDIS was giving her a lover that was NOT the Doctor. I was happy that she was happy. And how cool was it that Tom Milligan was the man who died for her in an alternate reality, even if he couldn't remember it?
But hello, here comes Doctor Who: The End of Time and Martha is with Mickey??? I think many, many fans cocked their heads to the side with that one and said "wtf?" I keep seeing posts going, "Okay, that's kind of awesome, but What happened to poor jilted Tom?"
I have a theory that has nothing to do with anyone being jilted, would you like to hear it? Great!
Martha is loyal to a fault. It took a year of absolute hell and her family being tortured before she finally left the Doctor, and even then she would have done anything for him. I find it hard to believe that she'd just abandon Tom, her fiance, for someone else, even if he is the dashingly brave and adorable Mickey Smith.
Also, Tom is a pediatrician. He works with children. What's more, he is a man we've all seen will die for what he believes in. Anyone guessing where I'm going with this? I don't find it a stretch at all that Tom might have found his untimely demise off camera during Torchwood's Children of Earth. The 456 wanted children. The governments of earth were taking them by force. Maybe sick kids were just as undesirable and therefore as expendable as poor ones.
And as far as Mickey persuading her to go freelance. Perhaps it wasn't so hard to persuade her once the very government she worked for was responsible for the death of her fiance?
We have no idea how far in the future the Doctor Traveled to save Martha and Mickey from that Sontaran. It could have been five or even ten years, plenty of time (with room to spare) for Martha to become a widow, be comforted by the lovely (and sooo ready to love someone) Mickey and to fall in love. So until I hear otherwise, the above is my personal cannon.
I'd write an epic fic to illustrate it all, but as a working mom with an infant I just do not have the time. I'm actually writing this while my son naps. So I'd love it if anyone else would like to take the idea and run with it. Just do me a favor and let me know, so I can read it.