Appears a combination of fear, physical beatings, Stockholm syndrome, and brain washing.
Ohio abductions: how could it have happened?
This article says it was her first chance to escape in the entire 10 years.
Cleveland captive tells police she took first chance to escape
It seems the goal is survival at any and all costs...with reconciliation with humanity/conscience if ever and whenever survival permits.
This explains why humans develop multiple personalities. When they need to compartmentalize to survive...they do what they need to.
Thx for your enlightening links.