Legal Question in Wills and Trusts in California

It is probably best to file a "Preliminary" I&E listing the assets you know about. Then a supplemental list can be filed later. If you cannot do that, you would need to file a petition for extension of time.

Mr. Jordan is correct. However, and in addition to his answe, I would advise you to obtain the assistance of probate counsel, as doing your own representation doesn't save you time or money in the long run; probate counsel can be paid out of the estate assets when the estate closes, and counsel payment must be approved by the court.