Ruth Westheimer, known worldwide as Dr. Ruth, says she’ll be sneaking into the audience tonight at Act II Playhouse in Ambler to see Mark St. Germain’s bio-play Becoming Dr. Ruth (through Feb. 17) and stay around for a Q&A afterward.

“I’ve seen the show a few times before,” Westheimer, 90, said by phone last week from New York. “I let them hide me in the back someplace, where the actress [at Act II, it’s Drucie McDaniel] cannot see my reaction.”

“Some parts are sad, of course. I was an orphan of the Holocaust,” she says. “But I have always concentrated on love of life, joie de vivre.”

Soon she’s also going to the Sundance Film Festival, where a documentary about her life, Ask Dr. Ruth, will be showing. It has already been picked up by Hulu and is going into general release. (Be advised that the official trailer here contains Dr. Ruth’s trademark frank talk about sex.)

“I like it very much, especially the animated portions about my childhood,” Westheimer says, “because I have very few pictures of those times.”

This media sex therapist, writer (40 books and counting), and commentator, is famed for using humor to discuss topics often attended by embarrassment or even shame.

But to hear her story, you wonder where the good humor comes from.

“I was an only child in a comfortable Orthodox Jewish household in Frankfurt, Germany,” she says. She was sent at 10 years old to Switzerland as part of the Kindertransport rescue effort, which saved her from her parents' fate of dying in the camps. “They gave me life twice,” she says, "once when they gave me birth, and a second time when they sent me away.

“So I concentrate on zest for life,” she says, “almost as a memorial for my family, who never had graves.”