The first thing you notice, of course, is the performance.

The tall woman with the dazzling smile, malleable face, and ability to pull off a sort of physical comedy that even she calls "a little reckless" fully commands a stage. If she's in a musical, she can envelop a house with a soprano voice that carries hints of a sultry mezzo.

And she can alter that voice with seeming ease. Currently, as part of the four-member cast of the Walnut Street Theatre's Forbidden Broadway's Greatest Hits, she delivers a spot-on parody of Ethel Merman. And then another unique singing persona, Carol Channing. And then Liza Minnelli, different still.

You check the program: It's Jennie Eisenhower.

Hmmm - you look up and wonder. Could it be?

Hard to tell - especially at the Walnut, where, with the cast's three other talented actors, she lovingly skewers myriad Broadway stars in the course of two hours.

But eventually the high cheekbones, the almond-shaped eyes, and that smile provide evidence of her direct connection to an American political dynasty.

The daughter of Julie Nixon and David Eisenhower, granddaughter of one president, Richard M. Nixon, and great-granddaughter of another, Dwight D. "Ike" Eisenhower, says that's not often noticed.

"People rarely pick up on it, unless they're told. Every now and then someone says, 'You look a lot like Julie Nixon. Are you related?' "

For Jennie Eisenhower, her provenance is a given, a point of pride, and "if people figure it out, that's fine." As for her career, she considers genealogy beside the point; she once instantly dismissed an agent's idea to exploit it, and she doesn't mention it unless asked.

Like her forebears, the busy Eisenhower, who is 30 and lives in Center City, operates in the spotlight, but on a very different stage - or stages.

"This year's been amazing," she says. She started off the 2008-2009 theater season as Mae, the strange den mother of the pot-smokers in the loopy musical version of Reefer Madness, which was literally a joint production, by 11th Hour Theatre Company in Center City and Montgomery Theater in Souderton.

She then went on to direct a production of Our Town at her Chester County alma mater, Conestoga High School, where she's the adjunct theater director and choreographer and runs the dance program. Then, back in Center City, she played the title role in Mauckingbird Theatre Company's intense, all-female Hedda Gabler, in which, she says, "the emotions were like, out there - it was very big."

After that, Eisenhower went back to Conestoga to direct Kiss Me Kate, then to the Studio 3 stage of the Walnut, where she was the left-behind wife eking out a spartan existence in Madi Distefano's production of Criminal Hearts.

After her current Walnut stint as umpteen characters in Forbidden Broadway - "I think it's something like 12. I count by wigs!" - Eisenhower will be off to the Bristol Riverside Theatre to play in Broadway Starlight, a collection of music from popular shows, beginning Aug. 13.

During all this, she has been teaching a roster of voice students in private lessons. Her packed schedule is emblematic of other similarly successful Philadelphia theater artists who find steady work because they are skilled in many areas. "I cast a wide net," she says - and she's just talking about auditions.

Eisenhower grew up in Chester County - both her parents are authors and her father, David, teaches at the University of Pennsylvania, where he's also a fellow in public policy. (A brother is a research assistant at Penn, and a sister works in New York with children who have terminal illnesses.)

After graduating from Northwestern University with a dual major in theater and communications, Eisenhower moved to New York, where she became disillusioned with what seemed to her the prospect of a nomadic future.

"I had in my head you'd live in New York and work in New York and have a house and a family there - but all you do is audition in New York to go working all over the place. You get a gig in California, you go there for three months. Then you come back, and you haven't been there, so you start all over again."

She did start all over for a short period - as a personal shopper at Bloomingdales. Then she was cast in Baby Case at the Arden Theatre Company in 2001, which "started me in Philadelphia, and started me looking at it as a town that has a really viable theater community.

"It's the best move I ever made - I love living here. You can expand and grow as an artist, without a lot of pressure. I love directing. I love acting. I like to teach voice. I'm so glad to be in a town where it's OK to do all of that."

She was born after Dwight Eisenhower had died, and is too young to remember her great-grandmother Mamie, but she was close to Pat and Richard Nixon - Ma and Ba to her. She says her parents encouraged her when, as a youngster, she felt an affinity for performance, and her grandparents "came to everything." In fact, she says, Nixon's last public appearance was at her 10th-grade performance in Conestoga High's production Into the Woods, "and he stayed afterward and talked with everyone and was in all the group pictures."

Asked about her parents' reaction to some of Eisenhower's, well, more way-out roles (in lesbian-themed Hedda, for instance), she laughs. "They're just glad I have a job," says the woman who has an ever-lengthening string of them.

Contact staff writer Howard Shapiro at 215-854-5727 or hshapiro@phillynews.com. Read his recent work at http://go.philly.com/howardshapiro.