(music-news.com) - Yoko Ono has defended Sir Paul McCartney's ex-wife Heather Mills, saying she must have "suffered". The 75-year-old Japanese artist, the widow of Paul's Beatles bandmate John Lennon, believes Heather's marriage to the legendary musician would have been a struggle for her. Speaking during a visit to Lennon's childhood home in Liverpool, she said: "It's not very easy for a woman to be associated with The Beatles. I think all the wives did suffer, but suffered quietly and endured." She added: "Heather needs to do her very best and try to survive." Yoko also expressed her sympathy for Paul over his bitter divorce battle with Heather, which was finally settled last month. She added: "I'm very sorry for him to have had to go through all that. "I haven't spoken to him about that but it's a subject which he probably doesn't want to discuss with other people." Yoko, who began her relationship with Lennon in 1968 and married him the following year, was accused by many diehard Beatles fans of being the cause for the band's break-up in 1970. Lennon and Yoko recorded a number of albums when he was still a Beatle, including 'Unfinished Music No.1: Two Virgins', 'Unfinished Music No.2: Life with the Lions' and 'Wedding Album'. Lennon, who famously staged a 'bed-in' for peace during his honeymoon with Yoko, was shot and killed in New York on December 8, 1980.