Interesting question. I was an actor in an audio recording of her book "Fairest". I met her only once, and she didn't have any family with her. I'm sure if you get in touch with her publisher you could get her contact info.
Gail Carson Levine's birth name is Gail Carson.
Her maiden name was Gail Carson. She has been married to David Levine since 1967. Instead changing her last name, she chose to use both her maiden name and her husband's name.
Gail Rodono's birth name is Gail Cottrell.
Gail Kainswarren's birth name is Gail Kaneswaren.
Gail Borges's birth name is Gail Monast.
Gail Devers's birth name is Yolanda Gail Devers.
Gail Neely's birth name is Beverly Gail Neely.
Gail Rebuck's birth name is Gail Ruth Rebuck.
Gail Kubik's birth name is Gail Thompson Kubik.
Gail Lynn's birth name is Gail Lynn Kathan.
Gail Marlow's birth name is Gail Alicia Marlow.
Gail Langford's birth name is Alice Gail Langford.