Mary Crawley came from a modest home in New York. She was very close to her brother: Matthew. They had the misfortune of losing their parents in an unresolved shooting when they were young. They struggled to make meet ends but none the less, Matthew worked hard to put his sister through medical school. She became doctor of Medicine, just in time to be able to diagnose her brother of dementia . She struggled a while to take care of him, but had to face reality and place Matthew at the Arkham Asylum. She quit her practice in New York to be close to him.
Two years later, Matthew was relieved of his suffering. After his passing, she continued to work at the Miskatonic University Hospital, where there was an opportunity to do research after hours. She didn’t know many people, being withdrawn, but her goal to help other like Matthew drove her forward.