Without reading all of the previous posts, I'm gonna say this...
At least her family welcomes you and wants you there. My SO's family wants nothing to do with me, meaning that I probably won't get to see him at all on Christmas Eve or Christmas Day. (they're good at coming up with ways to keep him busy with 'family stuff' so that he doesn't have TIME to get away ~ among other things).
Go. Have fun. Feel good and appreciated that her family wants you there. Don't worry about anything else. Enjoy the company of the family that you are talking about marrying into.
Happy Holidays!
