Is the sentence right or wrong?
Betsy: "I'll leave at five o'clock."
Betsy said that she'd leave at five o'clock.
We use "would" as the past of "will" in the reported speech.
Examples
Anne says she will come → Anne said she would come
I promise I will write → He promised he would write
They are sure they will be on time → They were sure they would be on time