My new golden retriever is aggressive toward children, runs away when it gets outside and lunges at anyone who tries to take her from my bed. What should I do?

Hi, I'm a "new dog owner"(My dad had a dog while I was alive and she eventually became my dog, but she didn't need any training.) We put her to sleep and I bought a Golden Retriever puppy. She's approximately 6 months old. She's pretty good most of the time. She took a beginner's obedience class and is pretty well potty-trained. The major problem is that she is aggressive. I was hoping I could tell you about it and you could give me a suggestion. When I give her a pig's ear, or some other special treat, I, or any other adult can take it away no problem. But when anyone younger than 14 tries to take it away, she viciously lunges at them. My sister had to get stitches in her forehead. The other problem is that she lunges and growls at anyone who tries to remove her from my bed or punish her. (We normally grab her collar and put her muzzle on.) The other problem is when she knows she is being bad she bolts away when you even flinch in her direction. When she gets outside by accident she doesn't come to you no matter what. She just runs away. I tried treats, toys, soft voice, and many other things. The problem lies in the children. They can't punish for biting because they're too scared to even touch her. What are your suggestions? Thanks. Respond quickly as you can.

Blake