Lieutenant Klein was a nurse who made a one time appearance in the Season 2 episode of M*A*S*H titled "5 O'Clock Charlie". The part of Lieutenant Klein is played in the episode by Sarah Fankboner who also played the part of Nurse Owens in "The Incubator" later in Season 2.
About Nurse Klein[]
In "5 O'Clock Charlie", Hawkeye and Trapper are trying to make a gigantic bulls-eye to help the inept Korean pilot 5 O'Clock Charlie hit the ammo dump. They approach Lt. Klein for four dozen sheets. Klein, who appears to be in charge of the Supply tent, protests that she can't do it, but Hawkeye persuades her with "Come on, Klein, you never turned us down before." He explains that he and Trapper "just met four dozen great girls."