Depends, was there a will? Were they married? (The word biological presumes no, but who knows) Not enough info to know what's going on. Someone has to see a Probate lawyer (Preferably one with family law experience) at this stage to sort this out.
There could still be a contest over custody. When did she pass? Where have the children been before she passed and since then. If the kids were with you and your wife there could be standing to get custody. Go talk to a probate attorney who has some custody expertise. The longer you wait the harder it will be. The children are more important than the possessions. If she had no will the possessions will go to the children.
IF YOU FOUND THIS ANSWER "Helpful" or " The Best Answer" YOU CAN THANK ATTORNEY RADDATZ BY MARKING IT SO because Avvo awards the attorney points. MS. RADDATZ is donating her time and talent by answering questions to help those in need of legal information. This is NOT a consultation and in no way creates an attorney-client relationship. YOU SHOULD ALWAYS PERSONALLY CONSULT WITH AN ATTORNEY IN YOUR LOCAL AREA who has specific expertise in the area of law you are asking about.
Remember that it is the Lawyer who: Punishes the wicked, Protects the innocent, Raises up the lowly, Opposes brutality and injustice, Seeks equality of humanity regardless of color, cast, sex or religion, Leads in every cause, and Seeks the best in everything.