From the Wikipedia article:

> The radar intercept officer in the rear seat, Lt. Matthew Klemish, initiated ejection for himself and Hultgreen as soon as it was apparent the aircraft was becoming uncontrollable. First in the automated ejection sequence, Klemish survived. However, by the time Hultgreen's seat fired 0.4 seconds later, the plane had exceeded 90 degrees of roll, and she was ejected downward into the water, killing her instantly.

It seems that she was just 0.4 seconds too late, otherwise she could have survived like Klemish.