Shes a quarter vampire and pika gajinka because of her parents not to many of them in the vault due to the fact that vampires are more rare in general and most gajinka fled back into space before the atomic war Id also like to add that Akira and Olivia are in two different universes anyways.

Born in vault Soaring Eagle Olivia lived a very peceful religious life based on character and strong values and principles a Native American girl of purity and honor like many of the vaults other reidents.

A little bible bashey but it was the world to her at the young age of 16 Olivia's Vault was raided by an unknown military wearing extremely advanced power armor that would even make the Enclave Jealous.

With no means of defense Olivia hid in a locker and witnesd friends and family Either killed or taken god knows where.

Sad that all her opportunitys with life in the vault that her ancestors thrived on were taken away
Her spirt remaind the same as well for her values.

With only her golf club and Electricity the young mouse went out to search for her fellow residents.