Erin Foster Shows Off Bond With Stepmom Katharine McPhee in New Photo

David Foster's daughter defends composer's 34-year age-gap with wife Katharine McPhee... despite being older than her own stepmother

David Foster’s Daughter Sara Defends His 35-Year Age Gap with Wife Katharine McPhee, Calls Her a ‘Sister’ Figure

Katharine McPhee Celebrates 7 Years of Marriage with David Foster, Jokes ‘We Still Like Each Other, Most Days’