Sarah Ferguson Quotes Queen Elizabeth at Lisa Marie Presley's Memorial: 'Grief Is the Price We Pay for Love'

Sarah Ferguson is remembering her friend Lisa Marie Presley with a quote from her former mother-in-law Queen Elizabeth II. Ferguson, 63, spoke at

Presley's Graceland memorial service on Sunday in an effort to "celebrate the extraordinary Lisa Marie" at an event full of her closest loved ones. "I stand here with

great honor because we called each other 'sissy,' and I've been with you all for all your lives really," the Duchess of York said. RELATED: Sarah Ferguson Mourns 'Sissy'

and 'Devoted Friend' Lisa Marie Presley: 'I Am Deeply Saddened' "Sissy this is for you with affection," Ferguson continued. "My late mother-in-law used to say that

nothing [that] can be said can begin to take away the anguish and the pain of these moments, because grief is the price we pay for love. And how right she was." The public

service was held on the front lawn at the Graceland mansion in Memphis, Tennessee, as family members Priscilla, daughter Riley Keough, half-brother Navarone Garcia, ex-husband

Michael Lockwood, their 14-year-old twin daughters Finley and Harper and late son Benjamin's girlfriend Diana Jay, all came in support of Lisa Marie. Elvis' only daughter died

Jan. 12 after being rushed to a Los Angeles hospital for a possible cardiac arrest at 54 years old.