Puppy misbehaviour

Question
We brought home a 5 weeks old german shepherd puppy a few days back and she's quite playful. (All her siblings were gone by the time we picked her up) Although the playfulness turns into very painful bites when she sees we're into it. I've tried to follow a few advises like yowling like a puppy to tech her it's painful when she bites rough or replacing my hand or feet with her favorite toy. Anyway, she's not very fond of her toys tough they all fit in her mouth and not hard to chew on. When she wants to play she immediately latches on our feet and bites us hard and even tugs on us. We're not making loud noises and we pet her gently when she's calm, but it worries me. She even jumps for our hands and want to bite it too. Do you have any advice we should follow to make her not chew on us but her toys and be less aggressive towards us?

Answer
She needed another few weeks for her siblings to teach her not to bite so hard.  Yowling and denying her your attention will eventually work.  Perhaps longer for being so young.  Young Labs, which I know best, and other puppies tend to very bad about biting. You see a litter of them, and all the ones that are awake are biting another one or themselves. I am not even sure they realize that when they are alone, if they quit biting, they would quit being bitten. At 3 to 4 months they are getting their adult teeth, and it seems they spend every waking moment biting or chewing. One thing you can do at that stage is to knot and wet a piece of cloth. Then freeze it. The cooling will soothe the gums. Only let the puppy have it when you are there to watch it. I maintain a Lab's favorite chew toy is another Lab. Otherwise they settle for any person they can. They keep hoping to find one that won't yelp, jerk their hand away, and leave.

You just have to keep on correcting them, hundreds of times, not dozens. Provide sturdy, safe toys such as Kongs and Nylabones. Avoid things they can chew pieces off and choke on them. Keep them away from electrical cords. Crates are essential for most young Labs and other dogs.

The pet stores are full of toys that many dogs will quickly chew up into pieces they could choke on or cause intestinal blockages. If you are not there to watch, stick to sturdy stuff such as Nylabones and Kongs. Keep a close eye on chew toys and quickly discard anything that is coming apart in pieces. Rawhide is especially bad because it swells after being swallowed. I don't trust any of the consumable chews. The dogs just gnaw them down to a dangerous size too quickly. These problems are the worst with, but not limited to, large, aggressive chewers such as Labs.