Why is my cat being a *****?

i have 2 questions about my cat.

1) I have a cat called iggy and she had a son which we kept called buzz. Buzz is a few months old now but iggy has started being really horrible to him and hissing and growling everytime she sees him. Why?

2) I recently went away for 2 weeks and I left my cats with the rest of my family (I am 16 and I stayed at my nans, so the rest of my family were still at home) and I got back yesterday and buzz was really glad to see me and still hasn't stopped cuddling me but iggy on the other hand is being really bitter towards me. She usually isn't like this to me- only to buzz but since I got home yesterday she has been really sour and is ignoring me. I am usually he only one who gives her attention because I raised her to be an attention whore (more than a usual cat lol) and she obviously hasn't been getting a billion cuddles a day for a couple weeks it it ought she would be glad to have cuddles again but she doesn't want any anymore? I do t know why