"Love your penis, Mike."

Dr. Ruth is on the phone with her moving man about packing up her apartment, but he suddenly says, as so many have, "Can I ask you something?" And as we all know, Dr. Ruth Westheimer has made her surprising celebrity career out of giving people sex advice. Unembarrassed, straightforward, wise, she's a Jewish grandmother who's an expert, not on chicken soup but on orgasms.

But sex is not the focus of Mark St. Germain's Becoming Dr. Ruth, currently at the Walnut's Independence Studio on 3.

Instead of therapeutic advice, which might be far more interesting, this is a biodrama presented as an autobiodrama. Jane Ridley is charming and convincing as the diminutive therapist who tells us the story of her life, a life crowded with husbands and historical events, beginning with her journey out of Nazi Germany when she was 10 years old.

The saga continues through her flight to Israel where, as a Zionist, she joined the Haganah, the underground army in Palestine (there is a great grandma-was-a-sniper moment when she shows us a paper target with five bull's-eyes from a fairground where she had amazed her little grandson). And so on to Paris, then to New York, where the magazine True Confessions helped her learn English. Eventually she earns her doctorate, gets a gig on the radio, and the rest, as they say, is history.

Under Jere Lee Hodgin's direction, the play uses three familiar devices as ways of punctuating and enlivening a solo show: the phone; packing up the clutter of her apartment and explaining it as she wraps; and us, the audience. As the play opens, she's on the phone, saying: "Wait. I have company," as the house lights go down and the stage lights come up. This establishes a cozy sympathy with us that endures throughout the 90 minutes of the show, so that the audience, moved by her Holocaust stories and her survivor's stamina, forgives her childlike pride in her accomplishments.

As Dr. Ruth packs photographs and books, she also bubble-wraps her collection of turtle figurines, explaining, "You have to stick your neck out." I wish St. Germain had stuck his neck out and taken more of a risk with this extraordinary woman's story and given us a more daring play.

Walnut Street Theatre's Independence Studio on 3; Through Dec. 27. Tickets: $35-45. Information: 215-574-3550 or 800-982-2787 or www.walnutstreettheatre.org