No. Regina King and Martin Lawrence do not have any children together.
Regina King was pregnant during the filming of the movie 'A Thin Line Between Love and Háte' (starring herself, Martin Lawrence, Lynn Whitfield and Bobby Brown) and didn't tell anyone until the movie was finished.
It's the film where she played the role of Mia, Darnell's (played by Martin Lawrence) childhood sweetheart.
In January of 1996, shortly before commencing work on Jerry Maguire, King gave birth to a son, Ian Alexander, Jr. King and the child’s father, Ian Alexander, Sr., an executive at Quincy Jones’ Qwest Records, were married in 1997.
Martin Lawrence has three children: Iyanna Faith (born November 9, 2000) and Amara Trinity (born August 20, 2002) with his first wife Shamika Gibbs, and Jasmin Page (born January 15, 1996) from his previous marriage to former Miss Virginia USA Patricia Southall.