(FORTUNE Magazine) – Earlier this fall, in a profile of Martha Stewart, a Vanity Fair scribe wrote that Martha was the second-richest self-made woman in America, ahead of Oprah (well, duh!) and behind Theresa Pan, owner of Pan Communications.

Theresa who?

It took us a few months to track down the elusive yet dynamic 54-year-old Silicon Valley resident. When we did, she presented a life very different from Vanity Fair's representation and wanted to set a few things straight. Go ahead, Theresa: "During the last year, I feel there were a lot of rumors around," she says. "Pan Communications [a PR firm] is totally unrelated to me."

In reality, Pan is no Oprah, but with an estimated net worth hovering below $600 million, she may be the richest self-made woman you've never heard of. After immigrating to the U.S. from Taiwan in 1974, Pan founded fiber-optic component maker E-Tek Dynamics in 1982. She retired in 1997 after selling a controlling stake in the company.

As for why you don't see her on TV, Pan's interests tend more to the altruistic. She runs a foundation mainly for Asian senior citizens in the Valley, and frequently travels to China, working to set up orphanages for abandoned girls. She also spends time with 128 horses at what she refers to as her "horse hotel." Pan doesn't see any similarities between herself and Martha or Oprah, though, when pressed, she confesses to being a good cook. (Watch out, Martha!)

--Julie Schlosser