How to teach 4 1/2 year old daughter to not to be so rigid with rules?

She is very rigid with her rules. She never eats or drinks if it is not her plate or cup. She sits in the same couch to watch TV. No one esle can sit on her part of couch. She never sits anywhere else. She doesn't touch other person's stuff. So, this means she also doesn't allow other kids to touch her stuff. So, sharing is out of question.How to teach my daughter that she need not be so rigid with rules? Or what should i teach her?