“I grew up on the battlefield. Conflict and Victory were my parents. The unit is my Life, my Family. I have no one except the unit.”-Olga
“Neither Enemy nor friend, just a messanger from the La-li-Lou-li-lo” (Patriots)-Mr.X
Olga was the daughter of Sergei Gulocovitch, an old Russian friend of Revolver Ocelot who had aided in the Shadow Moses incident (Such as providing the rogue FOXHOUND with a Hind-D helicopter). When Ocelot and Sergei planned to steal Metal Gear Ray from a Tanker in New York, she worked with them, although pregnant, keeping watch on the ship’s deck with various mercenaries from her father’s unit. There, she encountered Solid Snake, who tranquilized her-and then rescued her when Ocelot betrayed Sergei and sunk the tanker.
Shortly thereafter that, she gave birth to a girl. However, the baby was stolen from her by agents of the Patriots, and she was forced to work for Solidus and Ocelot during their capture of the “Big Shell” facility. After her father’s death she had full control of his mercenary unit, which now worked with the “Sons of Liberty” group.
There, Olga also assumed the role of “Mr.X”, similar to the Cyborg Ninja identity that Grey Fox had at Shadow Moses. This was, in fact, a deliberate move by the Patriots to ‘simulate’ events similar to Shadow Moses to collect information.
During the mission, she encounter both Raiden and Solid Snake at various times, with the latter telling her the truth of what really happened-that Ocelot had killed her father. She then knocked Raiden out, so he could be captured-a move calculated to have the Sons of Liberty lower their guard so that Olga and Solid Snake could slip onto Arsenal Gear.
After revealing that the Patriots had her daughter captive, Olga released Raiden (Eventually giving him her sword too-which Raiden would use not only to kill Solidus, but in his later adventures as a Cyborg Ninja himself.).
She would later be killed by Solidus, but entrusted Raiden and Snake with saving her daughter.
Which they did-and the daughter grew up to be Sunny, who was adopted by Otacon and pivotal to the end of the Patriots and Ocelot.
Despite never really meeting her mother, Sunny kept a picture of her onboard the plane the NOMAD….
and later (In Metal Gear Rising: Revengeance) Sunny would adopt an outfit similar to the striped outfit (actually fairly standard Russian navy equipment) her mother wore during the Tanker inciddent.