Audrey Melbourne, a 46-year-old Laurel trial lawyer, was appointed by Gov, Marvin Mandel yesterday to a vacancy on the Prince George's County District Court. She will be the first woman to be a full-fledged judge in a Prince Geroges Court.

Manel also announced the appointment of Graydon S. (Skip) McKee III, to another District Court vacancy. McKee, 39 h9, has been a juvenile master who has heard juvenile cases in the Prince George's Circut Court since 1975.

Melbourne and McKee will be filling vacancies left by the death of Judge Edgar Smith and the appointment of Judge Howard Chasanow to the Circut Court.

The District Court has general jurisdiction in misdemeanor (less serious) criminal cases and holds preliminary hearings in felony cases.

Melbourne will be the first woman to have full responsibilities in a Prince George's court, but she is not the first woman to sit on the bench in the county. In the 1950s, Nita H. Crane was a trial magistrate and heards primarily traffic and small claims cases.

Melbourne attended the University of Maryland Law School and has practiced law in Laurel for 15 years. She was among the first three woman to be accepted in the Maryland Bar Association, which until 12 years ago was closed to women.

When she began practice in 1962, she was one of about half a dozen women lawyers with offices in Prince George's.

In her most widely publicized case, Melbourne defended Kath Jusner, the first U.S. woman jockey, when she succeddfully appealed the Maryland Racing Commission's denial of her jockey's license.

McKee, also a graduate of the University of Maryland Law School, was a law clerk for Circuit Judge William Bowie before starting private practice before being appointed a juvenile measter in 1975 included the County Employees Credit Union and the Prince George's Hospital Credit Union.