Who said "Death may be cheerful to one who has lived long enough."?

This quote is attributed to Mary Shelley.

Death may be cheerful to one who has lived long enough. - Mary Shelley

"Death may be cheerful to one who has lived long enough."

Mary Shelley Death

Novelist English 1797–1851

"Nothing is so painful to the human mind as a great and sudden change."

"Beware; for I am fearless, and therefore powerful."

"Life and death appeared to me ideal bounds, which I should first break through."

"I have crossed oceans of time to find you."

"Death doesn't scare me anymore."

"Death and I are old friends."

"Welcome to my world."

"Death is just the beginning."