Sara Foster: The age difference between David Foster and Katharine McPhee ‘means nothing’

The age gap between David Foster, 68, and his fiancee, Katharine McPhee, 34, seems never to have surprised David’s daughter, Sara Foster. “He’s like forever young,” Sara told Us Weekly over the weekend. “His essence and his aura is that of like a 40-year-old. My 30-year-old friends have always wanted to date him. Always!” Sara, who’s three years older than her soon-to-be mother-in-law, added that those who take issue with the couple’s engagement “need to just get over it” and mind their own business. “[I’ve]known [Katharine] for a really long time, and I think she’s a really, really lovely girl,” said the “90210” alum. “The age difference means nothing.”