At 11 weeks you are firmly in the puppy shark phase. She will be incredibly mouthy because she's still teething. Think of it like a toddler, everything goes in her mouth. I doubt that her growling is true aggression, she's still learning how to interact with your family. Once she's done with all her shots you can get her into some obedience classes. Trust me, we have all been there - it's frustrating but she will get there. Try to redirect her from mauling the cat with appropriate chew toys and she will begin to learn what is appropriate behavior and what is not. You'll find this forum is a huge comfort when you think you're losing your mind!!!