My parents live near to my sister (the other side of the country to me). When sis had children, my parents looked after them while she worked until they went to school so they are v close.
My mum refers to my sister's children as "the children" or "the kids" regardless of the situation. I feel a bit put out by this as it makes me feel like my baby DS is not yet considered to be one of the family's children.
I'm being a bit precious about this, aren't I... I think I just feel a bit sad that my DS won't have as good a relationship as my DNs do with their grandparents.