Ah yes.....I do believe I did see a passing reference to Gina DeJesus having been a friend of Castro's daughter.
That's why she accepted the car ride from him, and wound up as his prisoner. She trusted him because he was her friend's father.
How does he kidnap his daughters friend and nobody notices? How can he keep them for years and nobody else know?
I really really doubt that noobdy else knew.
Not only was he the father of her close friend, but he was also her bus driver.