Natalia grew up in Terragrigia with her parents when she was a young age. During the events of Resident Evil Revelations you witness that the downfall of this city was caused from a bio-terrorism attack. During the conflict Natalia's parents were killed, but she managed to get to safety thanks to Neil Fisher. At that point she was taken into an care by TerraSave, before being captured by unknown people and taken to the island. Here she was the subject of some strange experiments, but eventually found herself free to roam the island on her own.
Alex Wesker is one of the candidates of Project W. This project, which was developed by the Umbrella founder Ozwell E. Spencer, aimed to produce a superior race of humans. She eventually managed to acquire control of Sushestvovanie Island, where she could use the population as test subjects to develop the T-Phobus Virus.
She kidnapped Claire Redfield and Moira Burton, amongst many others from Terra Save, to continue her experiments.