Never waste your money.
She told me never to waste ... money. What is the possessive adjective here?
My or your?
It depends if she meant the "generic" or impersonal you or you in particular.
If she said "Daisy, never waste your money. You've worked hard at that job of yours to earn it," then say "She told me never to waste my money."
But if you could rephrase what she said as "One should never waste one's money," she didn't mean you in particular. In that you can use "your" with the same meaning of a generic person.
[a writer, but not a teacher]