Does My Deceased Father Have A Child Support Obligation To My Mother?

My father passed away in July of this year and my mother is extremely upset that he hasn’t included child support provisions in his will. My sister and I (17 and 19) are both being left some money through a life insurance policy, as is my dad’s widow, but there is nothing stating that my mother will continue to receive child support payments.

My mother is EXTREMELY well off financially (~250k a year after taxes) and the lack of 1200$ a month does not put an undue strain on our family’s finances. She now is demanding, however, that my sister and I continue to make child support payments to her in lieu of an official arrangement for child support in my father’s will.

Does she have a leg to stand on in making my sister and I continue to pay her child support as (soon to be) two adult children attending university in Ontario?