Jenner and Scott are also parents to their daughter Stormi, 5.
Booker and Kendall broke up in October 2022 and it was reported that she was not looking for anything serious.
The couple had announced they were starting a family in January alongside a picture of the baby’s ultrasound.
This is the second child for the 34-year-old former reality star and 38-year-old stylist who are also parents to son Rowan.
The Kylie Cosmetics founder finally announced welcoming her son with rapper Travis Scott on February 2, just a day after celebrating their daughter Stormi's 4th birthday.
The lawsuit includes hostile work environment, racial and gender discrimination and retaliation.