NEWSErin Foster Gets Cozy With Stepmom Katharine McPhee After Sister’s ‘Child Bride’ Remark: ‘Fully Consenting Lady’
Erin Foster and Katharine McPhee shared a sweet selfie during David Foster’s charity celebration.
Aug. 11 2026, Published 4:43 p.m. ET
Erin Foster and Katharine McPhee got cozy at a family celebration just weeks after Erin’s sister, Sara Foster, defended Katharine against criticism over her 35-year age gap with David Foster.
Sara, 45, addressed the backlash during a June appearance on Kristin Cavallari’s "Let’s Be Honest" podcast.
"You know what? They're like 12 years in and they are happy," Sara said.
"She's a fully consenting lady, you know what I mean? This is not like some child bride. She is in her 40s," she added.
Erin Foster Reunited With Her Stepmom Katharine McPhee at David Foster’s Charity Event
Erin Foster highlighted daughter Noa’s playful bond with her younger half-brother Rennie, on her Instagram Stories.
On August 8, Erin, 43, shared a selfie with her 42-year-old stepmom from a banquet celebrating David's charity, The David Foster Foundation, per E! News.
The Nobody Wants This creator kept the caption simple, writing, "We had fun."
The family celebration also brought Erin’s 2-year-old daughter, Noa Mimi Tikhman, together with her younger half-brother Rennie, who is Katharine and David's 5-year-old son.
Erin highlighted their sibling connection with another Instagram Story, captioned, "Noa partied hard with my lil brother."
Katharine McPhee Became Part of David Foster’s Blended Family
Katharine McPhee became part of David Foster’s blended family after marrying the musician in 2019.
The latest family outing showed the warm relationship Erin had maintained with her stepmom, despite the unusual circumstances surrounding David and Katharine's marriage.
Katharine began dating David in 2017, and the couple got engaged the following year. They married in London in June 2019, before welcoming Rennie in February 2021.
Katharine had become part of a blended family that included David’s six children. His eldest daughter, Allison, had been placed for adoption after her birth and later reconnected with her father as an adult.
David also shared daughter Amy with ex-wife B.J. Cook and Sara, Erin and Jordan with ex-wife Rebecca Dyer.
- David Foster's Daughter Sara, 45, Defends His 35-Year Age Gap With 'Amazing' Wife Katharine McPhee, 42: 'Fully Consenting Lady'
- Katharine McPhee Is 'Managing' After Tragic Death of Family Nanny, Husband David Foster Reveals
- Katharine McPhee Celebrates Her Bikini Body Ahead of Turning 41: 'Loving Myself'
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Sara Foster Defended David Foster And Katharine McPhee
Sara Foster addressed criticism surrounding David Foster and Katharine McPhee’s 35-year age gap.
Sara opened up about her relationship with Katharine and how she viewed her stepmom despite their unusual family setup.
"Everyone has an opinion about something," she said.
"I am older than her," Sara added. "I look at her as a sister, but she is my stepmom."
Her comments came as David and Katharine continued to face public scrutiny over their relationship, which had lasted for more than a decade.
Sara Foster Praised Katharine McPhee’s Role in the Family
Sara Foster praised Katharine McPhee for building a close bond with David Foster’s older children.
Despite the attention surrounding their age gap, Sara emphasized that Katharine had formed a meaningful relationship with David’s older children.
"She’s really amazing," Sara shared.
She added, "I have to tell you she really is. It’s not easy coming into this family."
