Patti Davis said in an interview this week that although she and Reagan never discussed gay marriage, she believes he would have supported it, The New York Times reported Thursday.
"I grew up in this era where your parents' friends were all called aunt and uncle," Davis said. "And then I had an aunt and an aunt. We saw them on holidays and other times."
"We never talked about it, but I just understood that they were a couple," she added.
When serving as governor of California, Reagan, who died in 2004, joined Democrats in opposition of a ballot measure that would have barred gays and lesbians from working in public schools.
Davis said her father "did not believe that gayness was a choice," although "as a straight man and an old-fashioned man, it's not like he understood it."
Meanwhile, Phyllis Schlafly, a conservative activist and gay rights opponent, said she believes Reagan would oppose gay marriage.
"Of course, Reagan did associate with all the Hollywood crowd, and chances are he probably knew a number of gays," Schlafly said. "I could understand that he might not have wanted to bar them from a job but that would not mean he would want them to get a marriage license."