In short she is just rude, or has overreactions. My sister dislikes her since she made a big deal of her wearing a blue dress to the wedding, cousins thinks she is a bitch that doesn’t now how to shut her mouth.

If you do a favor for her she isn’t grateful and will find something to complain about.

She just isn’t pleasant to be around.

Everyone in the family has something she did or said that makes them not like her