Caroline Adama was the childhood sweetheart of William Adama, to whom he married. She is the mother of Lee and Zak.
Caroline was related to an important member of the Defense Council; it was partly through this connection that her husband was able to advance his career so rapidly (Scattered). Due to William Adama's commitments to the Colonial military, Caroline raised both children by herself. The strain of his absence and his committment to the fleet caused their eventual divorce.
She and Adama had little contact since their divorce, and at the time of the Cylon Attack, Lee had said she was getting married. (Mini-Series). It is presumed that she perished in the Cylon Attack, but officially this has not been mentioned.