So since Veronica is already a Fallout character, but comes from further in time than the period of the game this is how it works out:
Veronica is actually a wastelander who happened to wander into the Vault looking for shelter. Coming into contact with the vault, she was given implanted memories of being a Brotherhood of Steel soldier and then added to the group later on. This is because Vault-Tec/Enclave wanted to simulate how a typical BoS member would react to the environment, as a means of gathering data and deciding how to best combat one of their larger opposing forces.
However this won't be undone at the end of the game, because the effect of the memory creation was too strong. She will have zero recollection of her former life, nor connection to it.
Partial AU
Veronica is actually a wastelander who happened to wander into the Vault looking for shelter. Coming into contact with the vault, she was given implanted memories of being a Brotherhood of Steel soldier and then added to the group later on. This is because Vault-Tec/Enclave wanted to simulate how a typical BoS member would react to the environment, as a means of gathering data and deciding how to best combat one of their larger opposing forces.
However this won't be undone at the end of the game, because the effect of the memory creation was too strong. She will have zero recollection of her former life, nor connection to it.