All you have to do, really, is find your center about it. Know that the choices that you make are right/good/ok, and that you don't have to be like everyone else. And, you can defend your choices with "This is how we choose to do things, it's not up for discussion" which worked well for me with the ILs. DH ultimately told his mother (loudly): "Mom, *I am the parent, now back off!*"