My question involves estate proceedings in the state of: CA

My mother's father died in 2006, he has a will as far as we know. He has 2 sons living and 1 daughter, 12 grandchildren. His common Law wife was left basically in charge of his estate. We were estranged since the death of my mother. Is there a statute of limitations when to file? or what are the steps to take to find out what we are entitled to as his rightful heirs?