Check Out Katharine McPhee Rocking Matching Swimsuits with Son Rennie Months after Giving Birth

Katharine McPhee rocked a matching swimsuit with her baby boy and other family members in a new photo posted by her stepdaughter.

Katharine McPhee's stepdaughter, Sara Foster, shared the most adorable photo of the Foster women wearing matching swimsuits with their young sons.

In the photo, all the women and boys are wearing swimsuits in matching blue fabric from Foster's partnership with Summersalt for their collection Cotton Candy Skies.

McPhee is posed in a gorgeous one-piece swimsuit while she holds her baby, Rennie Foster, who is wearing matching swimming trunks with his mom and the other family members.

Foster shared the group photo of the family enjoying this sunshine on her Instagram story. Sara's sister, Erin is posed with a big sunhat, while her other sister Jordan is holding another young boy. She wrote over the image:

"The Foster sisters in Summersalt x SaraFoster."

McPhee gave the brand a shoutout on April 1 in her Instagram stories. She posted a photo of herself trying on a one-piece from the collection and wrote that it was the best one-piece she had ever tried on.

McPhee shares her son with her husband, David Foster. They welcomed him in February. A few weeks later, McPhee revealed his name and its origins during an interview with Hoda Kotb.

Recently the "American Idol" alum appeared on the show to sing a duet with one of the show's contestants.

Rennie is actually the name of David's great grandfather and a great uncle, so it is a family name. McPhee revealed that they had chosen the name a few hours before he was born.

She explained that during labor, the couple had still not decided on a name. However, her husband was on a family text group, and someone suggested it. McPhee loved the name and said:

"My husband said, ‘Hi, Ren Foster,’ and so we said, ‘That’s a good name. It’s a strong name."

McPhee has not yet shared a photo of her new baby on her Instagram feed. However, she has shown small glimpses of him in her story. She has also shared gorgeous photos of her post-pregnancy body.

For St. Patrick's day, McPhee shared a stunning photo of herself posing in a glamorous dark green dress that featured a side-split to show off her leg. She accessorized the look with a sparkly green face mask.

Recently the "American Idol" alum appeared on the show to sing a duet with one of the show's contestants. She sang Celine Dion and Andrea Bocelli's song, "The Prayer," with Willie Spencer.

The panel of judges, Lionel Richie, Katy Petty, and Luke Bryan, were blown away by his performance. McPhee looked amazing as she belted out the lyrics while wearing a pretty flowy pink dress.