Five Faifax County lawyers, including the first woman to sit on the bench in the county, have been nominated for two county lower-court judgeships that will become vacant in January.

The nominations were made by the Fairfax Bar Association and will be sent to the General Assembly, which will make the final selections at its 1980 session opening next month.

One of two nominees for an opening in Juvenile and Domestic Relations Court was Johanna L. Fitzpatrick, who was chosen earlier this year to serve as a substitute judge in both Juvenile and General District courts. tUnder Virginia law, attorneys are permitted to sit in the place of absent lower-court judges, a practice that has raised questions of the potential conflict of interest.

The other nominee for the Juvenile Court opening, which will occur when Judge Philip N. Brophy retires next month, was Michael J. Valentine, since 1975 has been a special justice sitting in mental commitment hearings.

Among the three nominees for the General District Court opening, which will occur when Judge J. Mason Grove retires next month, was Richard T. Horan, who was an unsuccessful nominee for a Juvenile Court judgeship in 1976.

Horan was reportedly turned down by the General Assembly because he is the brother of Fairfax Commonwealth's Attorney Robert T Horan, whose office takes cases to both Juvenile and District courts. Richard Horan has been a substitute judge since 1975.

The other two nominees for the District Court judgeship were Barbara M. Ardis, who serves as a commissioner in chancery cases and as a member of the Board of Zoning Appeals, and Alphonse J. Audet, who has served as a substitute judge in the lower courts since 1964.