David Foster’s children do not see any problem with his romantic relationship with much younger singer Katharine McPhee. In fact, one of the songwriter’s daughters has given her stamp of approval to Foster’s newfound love.

On Thursday, “90210” alum Sara Foster dished out to Us Weekly that she and her siblings totally approve of their 68-year-old father’s relationship with McPhee, who is 35 years younger. “We totally approve,” she said to the publication during an interview at the L.O.L. Surprise pre-New Year’s Eve bash in Los Angeles.

Sara went on to say that they are accepting of Foster’s girlfriend because McPhee is very good to him. She also admitted that she and her siblings are the type to be very vocal when something’s not right, implying that McPhee seems to have a very sincere intention of dating their dad.

“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,” the “Barely Famous” star said. “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 someone right now that really does.”

This Friday, a source close to Foster and McPhee also gushed to E! News that the couple’s romance is heating up. “David and Katharine are more serious than they ever have been,” the source said. “David and Katharine ave been spending a lot of time together and are not afraid to show affection now.”

The source continued by saying that McPhee has this positive effect on Foster who is typically a playboy. “David is usually a playboy but Katharine has made him change his ways, and he is really comfortable with her. He tries to fit Katharine into his schedule with dinners and lunches during the week.”

The producer and the “Smash” actress first sparked dating rumors back in May when they were seen getting cozy in Malibu. Then in September, the couple became very public with their romance as they started to step out together and attend public events as a pair.

Late last month, Foster and the “American Idol” alum were spotted kissing during a launch date in Beverly Hills. At the time, an insider said, “They aren’t hiding it anymore. David is really charming. The age difference might seem substantial to some, but they are really cute together and it makes sense.”