Katharine McPhee Foster's inner circle is defending her after her bikini photo caused quite the stir.
Erin and Sara Foster, whose dad is Kat's husband David Foster, showed their support for her latest swimsuit photo on Instagram on Dec. 29.
Things kicked off when David, 72, posted an image of Katharine rocking a black bikini and captioned it, "what baby," 10 months after she gave birth to son Rennie.
Some users criticized him, with one person saying, "Yeah, let's perpetuate the unhealthy narrative that women need to be back to or smaller than their pre-pregnancy size postpartum."
But Katharine, 37, felt differently and responded to the user directly. "Almost a year later after giving birth is an unhealthy narrative- go jump in a lake," she said.
The American Idol alum also created her own post to say that she had "zero" dieting and "zero" pressure to get in shape after giving birth. "Stop being so offended by what people post who have zero impact on your life and move on," the singer wrote this week. "Maybe you should have more of an attitude of like, let's say… 'oh that's nice he thinks his wife is hot.'"
Now, her stepdaughters are giving their take.
"If I can accept my step mom looking like this, you certainly should be able to," Erin, 39, wrote. "The photo wasn't altered or filtered and she's had no surgery. You can't shame someone for feeling cute after a baby whether she's sharing stretch marks or a six pack. Let her live."
Sara, 40, also pointed out a double standard for new moms. "If you [would have] had cellulite and stretch marks in the photo and the caption was exactly the same we would all be celebrating his post," she speculated. "But you don't and that's not allowed to be celebrated."
She then praised Katharine for her workout routine: "You have been working your ass off in the gym. Let's complain about women and husbands who post 3 week postpartum pics with their full body lipo, filters and altering apps that make us all feel like s--t," adding, "People are crazy." (David shares Erin and Sara with Rebecca Dyer, his wife from 1982 to 1986.)
Kat's Smash co-star Debra Messing also boosted her up, writing, "Brava! And send me your workout."
Katharine admitted she "found a great workout" and simply let her "body do its thing" after her pregnancy.
As she put it, "That's it. And guess what? I'll probably gain weight again at some point too. Who cares? BUT people freaking out about what my husband captioned seriously get a life."
Keep scrolling to take a look back at David and Katharine's relationship.
Rewind all the way back to 2006, when the pair meet on season 5 of American Idol. The record producer serves as Katharine's mentor on the singing competition, which kickstarts several musical collaborations and chance run-ins at celebrity events over the next several years.
In May 2017, eyewitnesses spot the undercover lovebirds enjoying a "very intimate" dinner date in Malibu. "By the end of the date, Katharine sat on David's side of the table and cuddled him with a blanket," a source shares with E! News.
Slam Dunk
After a fairly quiet summer, Katharine and David heat up once again at a Los Angeles Lakers game in November 2017. The Smash star also attends the performer's 68th birthday celebration alongside David's daughters Erin Foster and Sara Foster, as well as his stepsons Brody Jenner and Brandon Jenner.
The "Over It" songstress plays coy about the dynamics of their relationship in a 2017 interview with Health magazine, sharing, "We're very close friends, and we've been friends for a long time. I'm really, really fond of him, and I think he's an incredible person... People can say whatever they want."
Their talents unite during a star-studded holiday bash, where the couple performs lively renditions of "White Christmas" and "My Grown Up Christmas List."
Not so fast, you two. In January 2018, a source tells E! News the couple isn't rushing down the aisle: "David has not shown any interest in getting married again. He hasn't discounted how he feels about Katharine but there are no plans for them to even get engaged anytime soon."
Katharine and David show off their undeniable chemistry at the 2018 Met Gala. A red carpet to remember, no doubt!
In July of that year, E! News reports that David has finally popped the question while on vacation with Katharine in Europe. "Katharine has been wanting this for a while now," a source reveals. "David has been planning the engagement, but has kept it very secretive. Only a few family members knew about his plans."
Smitten
The two are smitten with each other at the 2018 Carousel Of Hope Ball. Katharine sizzles in a pink satin dress, while her beau opts for a classic tux.
Walk of Fame
It's a reunion! The couple supports and celebrates American Idol's Simon Cowell as he receives his Hollywood Walk of Fame star in Los Angeles in 2018.
It's date night! The two lovebirds attend Elton John's famous Oscar Viewing Party in 2018.
Red Carpet Ready
The couple poses for the camera on the red carpet at the 2019 American Icon Awards gala.
Think pink! The actress lights up the red carpet with her mesmerizing gown at the Breast Cancer Research Foundation's 2019 Hot Pink Party. Her man wears a traditional black and white suit.
After scoring the lead in the London production of Sara Bareilles' Tony-nominated show, the pair attends the press night after-party for Waitress: The Musical in 2019.
On June 28, 2019, the lovebirds tie the knot at the church of St. Yeghiche in London.
"Exactly 13 years ago today my very first single, 'Somewhere Over The Rainbow,' was released right after Idol. Today... I'm marrying the man who produced it," the bride posted on Instagram. "Life is full of beautiful coincidences, isn't it? Thank you for taking me over the rainbow, David."
In October 2020, a source confirms to E! News that the couple is expecting their first child together.
The American Idol alum gushes over the music producer on Valentine's Day 2021, sharing on Instagram, "My forever Valentine!! My best friend, my favorite person, my motivator, my everyday!"
In February 2021, news broke that Katharine had given birth to a baby boy named Rennie. She later shared a photo of her "boys."