Legal Question in Civil Litigation in California

If a probate has been opened, you should file a claim against the estate. If one has not been opened, you can open one and ask to be appointee executor. That'll really tick them off, but it will force them to deal with it.

You'll have to file a claim in the Probate court, and possibly sue her estate. If serious about getting legal counsel to help, and try to resolve this without litigation, feel free to contact me.

The signature does not need to be notarized. Did the note put the mobile home up as security? Her death does not change anything about the obligation to repay you except it is now her estate that owes you the money and not her. Write her relatives and point out that you ar entilted to the money back and she was paying you until she died and they would not want to dishonor her by refusing to pay a just debt [to irriate them]. If they do not agree to start paying you, file for probate, file a claim, and then you can collect from the estate if it is worth enough.