Ensign Clancy is an Enterprise-D officer seen as an assistant chief engineer during the Moriarty incident and later at the conn when K'Ehleyr comes aboard.
Clancy appears in two episodes of the second season. In Elementary, Dear Data she is on duty in main engineering as assistant chief engineer, minding the department while Geordi La Forge goes off to the holodeck with Data during the wait for a rendezvous with the USS Victory.
In The Emissary she is at the conn as the Enterprise-D is sent to collect the special envoy K'Ehleyr, who arrives in a cramped probe, and then races to intercept the Klingon sleeper ship T'Ong.
She is typical of the junior officers who filled the bridge and engineering stations in the early seasons, a role later taken by recurring figures such as Sonya Gomez and Ro Laren.