6-year-old granddaughter opens Christmas presents from her grandma a week before Christmas, grandma refuses to buy her more presents despite her mother's insistence: 'The mother wants me to let her take the original presents home.'

Why would she reward such bad behavior? 

One of the primary goals of Christmas is to inspire young children to behave well over the last couple of months of the year. The existence of a Naughty List and a Nice List always struck fear into my heart when I was a kid, and I tried as hard as I could to ensure my placement on the Nice List every year, back-to-back. Every parent knows that telling their young kids, "If you keep behaving badly, Santa might not come this year," is a foolproof manipulation tactic to get them to behave. Kids who wholeheartedly believe there's a chance Santa might not come will not mess around being menaces in the weeks leading up to Christmas. Kids who know that their parents will give in to them no matter what might try some major stunts in the weeks leading up to Christmas. Even if parents have no intention of putting their kids on the Naughty List, there need to be consequences if they knock down the Christmas tree like Dawn Davenport or open their siblings' presents early and break them. If a kid ruins Christmas, that's something they should have to live with that holiday season, no matter how harsh it might seem.