Ms. Davis, now 60, offered several reasons her father, who would have been 102 this year, would have bucked his party on the issue: his distaste for government intrusion into private lives, his Hollywood acting career and close friendship with a lesbian couple who once cared for Ms. Davis and her younger brother Ron while their parents were on a Hawaiian vacation — and slept in the Reagans’ king-size bed.

“I grew up in this era where your parents’ friends were all called aunt and uncle,” Ms. Davis said. “And then I had an aunt and an aunt. We saw them on holidays and other times.” She added, “We never talked about it, but I just understood that they were a couple.”

Once when she and her father were watching a Rock Hudson movie, Ms. Davis said, she remarked that the actor “looked weird” kissing his female co-star. She said her father explained that Mr. Hudson “would rather be kissing a man,” and conveyed, without using the words homosexual or gay, the idea that “some men are born wanting to love another man.” Years later, in 1985, Mr. Hudson died of AIDS.