Olivia Casta is a fake model. Behind her is Russian model Maria Tretjakova, using a filter similar to FaceApp's teen filter to make her appear much younger and change her facial appearance. Maria used to be active on OnlyFans and Instagram but is now only active as "Olivia Casta.".
Those pictures have to be fake
The Red Fox & Nancy A (I think)
Stunning. My absolute favorite model
https://pbs.twimg.com/media/Bp7FXt_CYAAm8Kj?format=jpg&name=900x900
(it exists in a better resolution but can't find it rn)