Will my cat ever like other cats?

I have a Maine Coon. Shes 8 months old and called Jess. I was thinking of getting another kitten for company (I have already reserved a male which will be ready in 4 weeks)...but i recently fostered a mother cat and 5 cats and ..Jess reacted real bad towards them - hissing, spitting, lashing out at anyone (ever me). Question 1 is that I am worry she will react this way to my 3 year old daughter if she touches her? (i love animals but this is not acceptable) Question 2: Will she ever accept a kitten? Should i tell the breeder now that she doesn't get on with them?