She was doing it with her male partner as a spotter. But he had waited too long, leaving her hanging for an entire minute while he was masturbating from getting highly aroused by seeing her convulsing in the noose. By the time he finally realized that he had waited way too long and started to take her down from the noose, she had a heart attack. Because of the sudden blood and oxygen pressure rush through her heart and brain, after the noose was removed.
But instead of calling medics right away he had only wasted very little precious time she had, by trying to resuscitate her. Obviously without any knowledge or equipment to do so with. Until finally grabbing his phone and calling for help. But it was too late. By the time the medics had arrived all they could do was to pronounce her dead.