Katharine McPhee on Her New HSN Jewelry Collection, Holiday Plans and Duets with Husband David (Exclusive)

Katharine McPhee has always had an “obsession” with jewelry.

“When I was younger in elementary school, people would trade their little Pokémon, but my girlfriends and I would bring in our rings from our little weekend vacations or trips,” the singer-songwriter and actress, 39, tells PEOPLE exclusively.

As an adult, McPhee — who describes herself as an “avid jewelry fan" — fed her passion by launching her own line, KMF Jewelry, last winter, which ultimately led to her latest project with HSN, the accessibly priced Radiance by Absolute x Katharine McPhee collection.

Working with the beloved shopping network was something McPhee aspired to as a designer and entrepreneur. She even holds fond childhood memories of her and her mom spending their Friday nights "gawking" at the bling sold on the channels. "It was our way of relaxing," she shares.

McPhee — who browsed thrift stores, antique joints and high-end department stores for good jewelry finds as a kid — says the inspiration behind the collection stemmed from a place of "wanting to pass on the love and tradition" she has with jewelry, which holds a lot of "symbolic meaning" in her personal life.

"So, I wanted to pass that on to people who can hear my story and hopefully be moved by what they see,” American Idol alum shares.

The collection consists of modern and contemporary rings, necklaces, bracelets and earrings decked out in simulated diamond jewelry designs. (Four of the styles are already sold out on the HSN website.)

The end goal was to create “substantial” pieces that could make a statement on their own or be layered with one another. Pairings like the Imperial Rope Pavé Bracelet, which is available in three sizes, and the matching necklace, are exactly what McPhee had in mind.

“It's for a woman who is more mature, but also for a young it girl who can rock just a cute, crisp white shirt and jeans and some pretty chic flats," she says of the collection. "I really tried to make it so that it was classic and universal for all ages.”

Out of the entire drop, her favorite is the Layered Cross necklace, which comes gold-plated or in silver.

McPhee’s work with HSN is only getting started. The Waitress alum adds that she and the team have released a near-exact replica of her emerald-cut diamond engagement ring from husband David Foster, 73, which is the one piece of jewelry she’ll never leave the house without — that, and her wedding band. 

Behind the scenes of creating Radiance by Absolute, McPhee actually turned to her beau for feedback.

“I always would run ideas by him, or I would show him pictures of things that I liked. I do specifically remember showing him the dog tags and the little initials," she tells PEOPLE. “He’s super supportive and excited for me, and I always love to show him the photos from the photo shoot. You always want to get your husband's approval."

She adds that Foster — whom she wed on June 28, 2019 — is always left “so amazed and proud."

To celebrate McPhee's HSN collaboration, the musical couple will take part in a special holiday performance from their new Christmas Songs album on Oct. 27 and fans can get their hands on an exclusive version of the record, plus an autographed Fosters Christmas Card, on hsn.com starting Oct. 25.

“I'm really excited about that,” McPhee says. “It's going to be really nice to be able to go on to HSN after I've premiered the jewelry line. We'll be talking about all things Christmas a day or two later.” 

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The holidays mean a lot to McPhee. She grew up in a household in which her sister, mom and late dad would throw up Christmas decor the day after Thanksgiving.

“I've tried to keep that tradition alive. Even without a husband and kids, I always did it. I think that the holidays are such a great time to become childlike and live in sort of a fantasy of your own.” 

Now that her and Foster’s 2½-year-old son Rennie David — who the couple welcomed in February 2021 — is “of age to really enjoy and understand" the festivities, McPhee has slowly built her own traditions, including an annual trip to the happiest place on earth. 

“I started this a couple years ago, after Rennie was born. He was really young, but my sister and her kids, my whole family, went to Disneyland during the holiday season. That's again [celebrating] that childlike fantasy,” McPhee shares. “It's such a fun, beautiful day. That's our Disney tradition.”