They have no right to take her away from her mother during the holiday season.
Holidays are often the only times of the year when people see their extended family. If you’re hanging out with your aunts and cousins every weekend, that’s great, but I think I speak for many of us when I say that seeing extended family merely once or twice a year is okay with me. Sometimes, you want to see them even less than that, and I’m here to tell you that is okay. Nobody should be forced to see anyone they really don’t want to hang out with, no matter what time of year it is. When you’re a kid, you’re often stuck with whatever family members your family wants to see in November and December. But when you grow up, you can really create your own holiday traditions with your kids, and if you don’t want Great Aunt Susan to be part of it, you are allowed not to invite her. It can be difficult to exclude people from Christmas and Thanksgiving, but sometimes it must be done.