—What, people call you the Doctor?
—Well, I’m not. As far as I’m concerned, you’ve got to earn that title.
One of the things I’ll always appreciate about Martha is that we got to see her in action as a doctor so often. This wasn’t a token job or a career. This was an essential part of her character. She was given real opportunities to act as a doctor, from performing CPR, to treating concussions, and even re-setting dislocated shoulders. And it influenced her every action; she’s just been kidnapped and drugged by Cheen but she’ll be damned if she let’s Cheen continue to use one of those patches while she’s pregnant. And being a doctor was so integral to her narrative, factoring prominently in her conflicts for respect. This was especially true with the Doctor, from their first interaction to her eventual departure.
You really gotta love Martha, the doctor.