The 75-year-old - who was married to McCartney's Beatles bandmate Lennon until his death in 1980 - insists it was hard being married to any member of the group.
But Ono has urged Mills to 'stay strong'.
She says, "It's not very easy for a woman to be associated with the Beatles. I think all the wives did suffer but suffer quietly and endured."
Yoko also says the mother-of-one "needs to do her very best and try to survive."
Mills won $33 million (GBP16.5 million) cash and assets worth $15.6 million (GBP7.8 million) last Monday (17Mar08) following the breakdown of her four-year marriage to McCartney.
Source: WENN