I think I'm unreasonably angry with this but never mind...
So Georgia, who also happens to be an architect, kills Paula's daughter in a hit and run.
Paula then spends the rest of her days pretending her daughter is alive as a coping mechanism but gets a job with her child's killer.
Paula takes Georgia's car - we don't know why - and stores it.
Kay finds this out so Paula kills her. Georgia felt unable to tell anyone this.