I've just realised something crazy.
Spoiler:
The 12 babies who grew up to become the Messengers, including Olivia and Pallid Man's mother, were created from Olivia's DNA (that detail completely slipped my mind), which means Olivia's mother is also her daughter and they're both their own grandmothers And Olivia is both sister and grandmother to the Pallid Man
And then there's the whole cool time loop with how Olivia's mother's DNA was used to create Olivia, leading to Olivia's DNA being used to create her mother etc.

As I've said before, this show has the most fun with the time travel concept