Greg responds...

She doesn't. She has twelve sisters. And seventeen brothers. And something like 300 cousins.

And the Martian race is still alive and well in the Earth-16 Universe. (From my point of view, killing them off wasn't the greatest addition to the Martian Manhunter mythos. It's stealing from Superman's schtick. Superman is the last Kryptonian. Martian Manhunter wasn't the last Martian for years and years, until that notion was added or retconned or whatever you want to call it into J'onn's backstory.)

And that's NOT why Martian Manhunter came to Earth. At least not originally when he first appeared in 1955 and not in our continuity either. He was brought here as a result of a Zeta-Beam accident.

Wow. Revealed way more than I planned to. Oh, well.