I believe in an adage: speak to kids about kid things, and adults about adult things. I personally would deal with this with your ex. At a drop off or pick up: "By the way, D said you said X. I would point out that my support is $3k and cover 70% of the kids expenses. I do not think it is fair for you to make comments about money to the kids. If you have a problem with anything address it directly with me and keep the kids out of the middle of it."
Definitely good advise. Hopefully you are dealing with a more reasonable person than my X.
Divorce Poison is a good read if she keeps up the BS.
"What is best for my kids is best for me" Amor Fati Link to quotes: https://www.divorcebusting.com/forums/ubbthreads.php?ubb=showflat&Number=2879712
