Why does Sarah Ferguson have NO Relationship with the Royal Family!?

I think it;s so sad that she spends Christmas all by her self, while her kids and ex hubby are at Sandringham, a beautiful estate, having a great time with the rest of the Royals. Plus, she wasn't even invited to the royal wedding! Shocking! I love Fergie, she always makes me smile and laugh when I see her on the tv, computer, etc. She's such a great person, i don't understand why they hate her so much!