Back before she’d first left earth with the Doctor, Martha’s biggest worries had been her father’s mid-life crisis, and whether or not she’d pass her medical exams. Now, those things had paled to insignificance. An insane Time Lord was holding her family, the Doctor, and Jack prisoner aboard a flying aircraft carrier, torturing people for pleasure while he worked on destroying the earth.
On top of that, everyone was depending on her to spread word of the Doctor so he could set things right.
If she succeeded, most people would never remember any of this. They were the lucky ones.