"Oh, yes, I think I will, Marilla," returned Anne optimistically.
But Anne, with her elbows on the window sill, her soft cheek laid against her clasped hands, and her eyes filled with visions, looked out unheedingly across city roof and spire to that glorious dome of sunset sky and wove her dreams of a possible future from the golden tissue of youth’s own optimism.
There are no more uses of "optimistic" in the book.
Show samples from other sources
I’m optimistic that I’ll get into a good college.
She keeps telling me her chances of dying in a car accident are 1 in 112, but I keep telling her that’s too optimistic if she drinks while intoxicated.