Why does the maid refuse the bachelor's marriage proposal in "The Apple Of Contentment" by Howard Pyle?

The maid refuses because she is already married.

She : "Now, you may ask me wh't you please, For anything I care."

He: "Then will you marry me? For we. W'ld make a goodly pair."

She: "I thank you sir; your offer, it Is most extremely rare. But as I am already wed, You'r late, sir, for ye Fair."