Gilbert is seeking joint custody of their 15-year-old son Michael Boxleitner.
The name stems from Gilbert's Little House creator and star Michael Landon.
The actress says Stone wrote the audition scene for her in order to get revenge after she had embarrassed him at a nightclub.
This backs Stone's rebuttal that no such scene was written purely for Gilbert's audition.
They dated on-and-off for over a year, engaged twice and then broke up.
Later, Gilbert met Bo Brinkman and became pregnant again, giving birth to a son, Dakota, on May 1, 1989.