Why do people blames other for something they haven't done and without actual evidence to back up their claims?

[Anonymous]

I just found out my sister, who I had a falling out with, is blaming me for being the reason why she is not allowed to come over for Christmas when I had nothing to do with this at all.

It was a decision made by our brother and our dad, who my baby and I live with, because our brother has never been into Christmas and our dad genuinely hates having everyone come here. Anytime he has visitors, he is ready for them to leave after an hour because he starts to get quite tired and he just wants to lay down. Despite having absolutely nothing to do with this decision, my sister is telling everyone I'm the reason why she can't see dad at Christmas, and people are believing her. It's so damn frustrating to have people hate me when I haven't done many of the things my sister is accusing me of doing.

Updates

+1 y

She is allowed to visit whenever, nobody is stopping her. Our dad is quite unwell and he cannot eat. He especially cannot stand for long periods. He is also battling depression. All of this things are things people are aware of. These are contributing factors for why dad doesn't want Christmas lunch and everyone coming here for 4 to 5 hours. Our brother hates Christmas all together.