David Foster's Daughter Sara Approves of Katharine McPhee!

Katharine McPhee has the approval of her boyfriend David Foster‘s daughter Sara!

The 36-year-old Barely Famous star opened up to Us Weekly about her dad’s relationship with Katharine, 33.

“We totally approve!” Sara said. “I mean, listen, we approve of whoever is going to be good to my dad at the end of the day and we’re very honest about it. If we ever thought that anyone was in something for the wrong reasons, we would be very vocal about it. We just want someone that’s going to treat him well and that cares about him, and I think he’s with someone right now that really does.”

“[Katharine] is a grown ass woman. She’s not 20, she’s turning 34. And my dad is very young. He’s like a very young, young dad/grandpa,” Sara added.

Kat and David were spotted kissing after a lunch date a couple weeks ago!

Pictured inside: Katharine doing some shopping at the Prada store on Rodeo Drive on Friday afternoon (December 15) in Beverly Hills, Calif.