You may also be looking for the similarly-named Ensign Masaro.

Ensign Massaro was a female member of Commander Charles Tucker's engineering team on board Enterprise NX-01.

In 2153, T'Pol ordered Sim, a clone of Tucker, to assist Massaro in running a diagnostic on the plasma assembly, as part of the crew's efforts to escape from a polaric field in which Enterprise had become trapped. (ENT: "Similitude")

This character was only mentioned in dialogue.