Hello,
I have a Cat called Jessica, she is a mother of 4 kittens.
Ever since Jessica born 4 beautiful babies and her sister (Buttons) got hit by a car,
Jessica was very protective,
When we got of 3 kitten's, Button's came out of the cage to be heeled in.
Purdy (the female tabby of Jessica's kittens) started playing Buttons when Buttons was free,

In a couple of day's Jessica started hitting, Purdy and Button's but didn't hit the oldest cat we have of all (Poppy).
Every time Jessica sees Buttons or Purdy she runs up to them and whacked them (not play fighting proper fighting)

My question is...
Q) Why is Jessica hitting Purdy and Buttons for no reason?