Diane Verlaine was the captain of the M-class Starship Torrens. She escorted Amanda Ripley on a mission to her mother, Ellen Ripley, who disappeared 15 years prior which eventually led them to the decommissioned trading space station, Sevastopol.
Throughout the game Verlaine makes attempts to contact anyone aboard Sevastopol however her transmissions are blocked by APOLLO which has strict orders from Weyland Yutani not to allow any communications to or from the station.
By the end of the game when Ripley has managed to bypass APOLLO control and directly tune Sevastopol's satellites towards the Torrens she instructs Ripley on how to board the ship. However, when Ripley does she finds a Xenomorph aboard and is forced out of the airlock, meaning Verlaine was likely ambushed and killed.