Robin Williams took a breather — as best as a breathless monologist could — from his current national standup tour to tape an interview for this Sunday’s “Conversations from the Edge with Carrie Fisher,” to air on the Oxygen network. According to quotes released by Oxygen, Williams, 49, had a good time with writer-actress-TV host Fisher, 45. Serious for a moment, Williams discussed coping with the loss of his mother, Laurie Williams, 79, who died shortly before Sept. 11 and whom he described as a stylish Southern woman. “My mother was a Christian Dior Scientist,” he said. “A Christian Dior Scientist is a person who believes that you can heal yourself, except when it comes to plastic surgery.” Despite her sometimes-eccentric nature, Williams’s mother was always the center of attention, said her son. “She would work the line when I brought her to a premiere. She is the only woman who ever made Joan Rivers speechless. We had a premiere for ‘The Birdcage,’ and these drag queens were going, ‘Oh, your mother is fabulous.’ They thought she was a drag queen. I had to say, ‘No, she is real.'” Williams, who was born in Chicago but went to college in California, also talks about growing up Episcopalian and serving as a choirboy and an acolyte. “Episcopalian is like Catholic lite,” he explains. “You don’t have confession in the Episcopalian Church. You basically have Thanksgiving where everyone gets hammered and goes, ‘Your uncle was a queer.’ They confess things there.” Amen, brother.