So how’s it working for everyone? Arnett, previously known for what he sees as misunderstood connivers on Arrested Developmentand 30 Rock, loves playing a nice, normal guy. He admires Applegate’s approach to work-life balance: “Christina has set out to give Sadie this great environment, and she does it every day. She works hard on the show, but she really carves out time—Sadie is there a lot.”

To boost the serenity factor, she splurged on a Malibu beach house. She took it to heart, not long ago, when Stephen Stills, 67, gently suggested they all make the best use of “ETR”—estimated time remaining. There is no room in Christina’s world for recrimination or regret. “I don’t do anger,” she says. “It makes no sense to me to hold grudges or pine over things. Or overanalyze.”

There are some things it’s just best not to question, including her new friendship with 64-year-old Stevie Nicks. Nicks says she was “having a little TV night” at home when she saw the episode of Up All Nightin which the actors segued into a wee orgy of intense Stevie-worship, belting out her hit “Edge of Seventeen.”

Nicks got on the phone and insisted on guesting as herself. To shoot Night’s duet with Applegate, she raided her wardrobe vault for the lacy outfit she wore on her Bella Donnaalbum cover, circa 1981—“right down to the boots and leg warmers”—and offered it to her young costar. When she first spotted Applegate in her vintage togs, Nicks recalls, “my eyes filled. It was like looking at my sister, years ago, standing there.”

Applegate fingers the thick gold crescent moon suspended from a chain around her neck, a powerful amulet she wears every day: “The moon was a gift from Stevie. I like to tell people that, because I’m still in awe. She also gave me all these.” She holds up her right hand, displaying three rings of filigreed gold.

A huge smile breaks, and her gaze focuses on the love object reeling toward her. After making a beeline for a tiny rocking chair, Sadie traces the letters painted on it and recites, “S‑A‑D‑I‑E.” Her mother looks stunned that the 18-month-old seems to know part of the alphabet.

“Sadie? Sadie, did you just say those letters? Sadie, where’s Papa?”

The baby makes a grab for Applegate’s crescent-moon charm, now tangled with the scripted gold initial Sshe’s also wearing.

“Whoa,” says her mother. “This is all going way too fast.”

GERRI HIRSHEY recently collaborated with Ronnie Spector on the ex-Ronette’s one-woman show, Beyond the Beehive.

Next: Women We Love on TV

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