Dawson, 38, found her relative, Vanez Ines Vasquez, 26, lying unresponsive inside her Venice residence last Thursday, TMZ reported.
The “Sin City” star immediately called 911. Emergency responders rushed Vasquez to an area hospital, but she could not be saved.
Vanez had suffered from hypertension as well as recent migraines, according to the celebrity gossip website.
Early autopsy results point to Vasquez dying of natural causes, the site reported.
The Post reported this week that Dawson’s family members are eyeing to buy low-income apartments in a newly renovated East Village building as part of a city program that converts derelict housing into affordable co-ops.