Cat acting weird after giving birth?

My cat had kittens nearly 2 weeks ago. This isn't her first litter but it's the first time she's ever acted so jealous.

Up until tonight she has been fine with us holding the kittens (just like every litter before) in fact she's brought us them and she's laid with us and them before.

She also has never been much for petting or affection, until this pregnancy. But she's only clingy to me.

All was fine until tonight, she threw one of her kittens and then left it ( i mean she actually threw it. It was in my lap and she picked it up with her mouth and threw it to the floor, then jumped down looked at the kitten and walked off.)

She also attacked another one of our cats after I gave him attention. The night her kittens were born, he looked at them and sniffed her bed, she didn't do anything. They were fine with each other. But a few days later when I was holding him (no where close to her kittens and we weren't bothering her) she left her kittens and jumped up in my lap to attack our other cat. He's scared and won't come back in the house now.

My mom is also worried about her attacking her. Every time my mom shows affection for me around her, she gets very tense and even growls.

This is all out of character for her and I have no clue what to do.