The same article of the will also gives Ms. Anderson far more valuable things: $100,000; a townhouse in the West Village worth more than $4 million; a beach house in Water Mill, N.Y., that is on the market for about $750,000; the contents of Ms. Morris’s safe deposit box at a bank; a carousel horse; and several paintings.

But the distribution of these bequests comes after a clause that says Ms. Morris makes these gifts to each individual “provided that he or she survives me by 30 days.”

Other articles make specific gifts to friends without this 30-day clause. And as in any will, there is a residual clause, which sweeps up whatever is left and, in this case, leaves it to three charities.

The three charities — the Natural Resources Defense Council, Doctors Without Borders and Save the Children Federation — with the State of New York joining them, contend that since the elder Ms. Anderson did not live 30 days after Ms. Morris died, she did not fulfill the requirement of the bequest and so what was meant for her goes to the charities.

Ms. Anderson’s daughter and her lawyers contend that this is a misreading of the will’s intent. The lawyers note that by law you cannot disinherit a spouse. Depending on the state, a spouse is entitled to some percentage of the estate, at a minimum. That Ms. Morris and Ms. Anderson were together for so long would make them like spouses, if they were a heterosexual couple. Therefore, they argue, Joan Anderson should not be cut out of the will because she died just 12 days after Ms. Morris, and her daughter should inherit the money.

The charities’ lawyers said Ms. Morris had chosen not to marry and had also been specific with the drafting of the will and the naming of three charities she supported during her lifetime.