My opinion is based on the fact that I am an atheist, raised by an agnostic and an atheist, but having very religious grandparents.
My parents never forbade my grandparents to give their daughters religious items. They explained to us that, to our grandparents, those items were meant as protection or for religious reflection and that it was up to us girls to decide if we wanted to display or wear them (I remember this from as early as 6 years old). Same thing for any folkloric item (such as evil eye talismans), things from other religions, etc. We didn't have overtly religious items in the public areas of the house, but if I wanted to display a nativity in my room, it was up to me. Personally, I like this approach.