Legal Question in Credit and Debt Law in California

That's a very involved question. The simple answer is that the wife has to open a probate court case and go through the probate process in which the court gathers the relevant information about the decedent's assets and debts, orders the debts paid if necessary (some debts like mortgages can be continued by whoever gets the house, for example) and orders the remaining assets distributed according to intestate (no will) succession laws. The specifics of how that all works and who gets what assets is much more complicated and is specific to the list of surviving relatives and what relation they are to the deceased.