The 40-year-old had three children with Mayweather.
Harris was found unresponsive inside her car outside the house and declared dead on the spot.
Investigators however don’t suspect any foul play.
Mayweather served a two-month sentence in 2012 after an incident in September 2010, during which Harris claimed he stormed into her Las Vegas home as she slept and attacked her.
The boxer was convicted of misdemeanor domestic battery, but claimed he was only found guilty because of his image.