just wait for the right time that your parents will tell you the real deal... in God's time you will get to know everything... just be greatful that both your parents are there for you...
pretty sure until this time your mother is still hurting after all those things she'd been through... and sure enough that you dont want her to see u sad or anything..coz it will just add to the pain.. just be open to your parents and tell them that whenever they feel like telling you everything..you are far more ready to hear them...