I would assume if the estate was settled then there is nothing more the state can do. Also I checked and the IRS has 6 years to audit you from the date of filing.
The estate was fairly involved unfortunately. We did however sell her house before the audit, so there shouldn't be any further issues with the valuation of that.
Her will created a business (LLC) which is tasked with selling her life's artworks (some 2,000+ pieces)... so we're of course keeping everything related to her works. We forever need to refer back to the estate valuation of each work whenever we sell a piece in order to report the gain/loss.
But... all this crap from her personal returns from years past is what I want to toss where possible. She kept friggin' everything... housekeeper schedules/records, dry cleaning receipts, meal receipts, bank/credit card/investment statements, cancelled checks, travel expenses, etc. The paperwork adds up!
Most of her personal stuff (correspondence, speeches, writings, and anything pertaining to her career) is off at archives at the Smithsonian (pre-1995) and UCLA (1996-2011).