(CNN) — Danica McKellar is most famous for portraying Winnie Cooper, the childhood sweetheart of series protagonist Kevin Arnold on “The Wonder Years.”

Fame came to the actress rather early, but rather than succumb to the negative pitfalls to which many child actors fall prey, McKellar found her saving grace in mathematics. She is so passionate about math, she has just released her third book on the subject, “Hot X: Algebra Exposed.”

McKellar approaches the often-terrifying subject of algebra in a playful manner that aims to make math fun while using effective lessons.

But as the former actress and musician talked with Oprah Winfrey for the second time this week — this time about the firestorm that erupted from her hour-long interview Wednesday — she said she doesn’t regret writing her memoir, “High on Arrival.”

“I understand this is a difficult thing for my family,” Phillips told Winfrey via satellite Friday, “but nobody’s talking about this, and if I’ve started a national dialogue, then I’m forever grateful.”

Phillips said she has gotten letters and Facebook messages from incest survivors, thanking her for coming forward.

“It’s been heartening and heartbreaking at the same time,” she said.

John Phillips died in 2001.

Two of his former wives, however, have vehemently denied Mackenzie Phillips’ accusations.

In “Harry Potter and the Half-Blood Prince,” the sixth film in the Potter series, he’s like a marathon runner who senses that he’s got this course beat: He’s still pacing himself, but there’s a definite spring in his step.

Potter’s confidence seems to be a product of Daniel Radcliffe’s authority in the role as much as anything. He’s decided he’s the hero of the piece, and he’s happy with that; Radcliffe plays him with such implacable conviction and such lightness, it’s becoming harder to worry about the character’s plight.

He can be reckless and impatient, but by now he’s essentially untouchable. His chums may be prey to hormonal surges — buckets of screen time is devoted to Ron’s love life and Hermione’s lack of same — but our Harry stays focused. While Ron moons over his girlfriend, every night Potter takes a textbook to bed with him.

Warner Bros.’ adaptation of J.K. Rowling’s penultimate Harry Potter novel, “Harry Potter and the Half-Blood Prince,” was originally scheduled to be released last fall, but the studio moved the flick to this summer for strategic financial reasons. Furious fans protested with petitions and pranksters mocked their outrage with viral videos, including one that cast Hitler, in his bunker scene from “Downfall,” going apoplectic over the movie’s delay.

But at last, the wait will be over on Wednesday. And that anger won’t linger for a film Hollywood insiders expect to be one of summer’s biggest hits — not least because it’s rated a family-friendly PG, whereas the last two Potter films were PG-13.

(AP) A softcover copy of the first Harry Potter book has sold for just over $19,000, according to a Dallas auction house.

“Harry Potter and the Philosopher’s Stone” was one of only 200 copies from the first printing issued with illustrated wrappers by London publisher Bloomsbury. The 1997 work about the boy wizard was published in the United States as “Harry Potter and the Sorcerer’s Stone” and includes an illustrated card signed by author J. K. Rowling.