I find it interesting that your sister insists she wasn't rude, while your dad insists she was. I can't see what writing sentences is going to do to do resolve that. It sounds like a communication and perception problem to me, that needs talking out and examples.
The whinning ... young girls do that. The problem is, they tend to get results with it, and so they keep it. If ignored, it is more likely to go away.
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Mom to an amazing young adult AS son, plus an also amazing non-AS daughter. Most likely part of the "Broader Autism Phenotype" (some traits).