Well, your character's actual mother could be:
-- Dead.
-- In prison.
-- Back in the Phhilippines for some reason.
-- Working at a high-class job, such as in a medical research center, which takes all her time, but she knew and trusted the Havens to take good care of Chilena.
-- Widowed once, and now married to a man who doesn't get along well with Chilena.
OR....it could be Chilena who caused trouble sometime back and Eric and Cecilia Havens for some reason were better able to handle her.