E.
Wow...I am so sorry. You never want to hear your lil ones using words like that, especially about YOU!
She doesn't know how hurtful these words are. When she says it, tell her that those are mean words that hurt your feelings. Do not get into it with your ex though. Once they know it pushes your buttons, they might have lots of fun at your expense. Just deal with the stuff your daughter says, as if you had no idea of the source. You will have to equip her to not blindly accept her father's words and actions. If she comes back with "Daddy says it" then tell her that that may be true but you do not allow those words at Mommy's.
I will be praying for you, hon. Try not to take her words personally. Consider the source and remember that being happy will be your best revenge. :)