Daughter Wants Everything Other Kids Have

My daughter has a tendency to steal other kids sippy cups (especially her 2 year old cousin Paris). She even does this even though she has the exact same thing in her cup. She will stop at nothing to get what she wants. She will hit, bite, pull hair, and scream. For someone so tiny she is fearless and mean. She will even do it to her much older cousin's. I try to correct her behavior by telling her NO and saying that's not nice. I will on occasion pop her hand or butt, or take her out of the room. She threw a fit at her cousins first birthday party cause she couldn't get his sippy cup (even though she had her own) and kept stealing a family friend's baby girl pickles. She is not a little meanie all the time and will share her food and sippy. She will also give love and kisses. She plays well with other's for the most part. I just wish she was a little less attitude sometimes.