A big part of the problem here is that Pepper left her litter mates when she was too young. It's usually recommended that puppies stay with their litter mates until they are at least 8 weeks old. Once they are able to do more than eat and sleep, puppies spend a lot of time playing with their litter mates. If Puppy A bites Puppy B too hard, Puppy B will yelp and end playtime for a couple of minutes. This is how puppies learn the power of their own mouths and begin to develop bite inhibition. Pepper did not have enough time to learn how to do that with her litter mates.
That's all in the past though, so going forward, you need to make it clear to Pepper that once she starts biting or clawing, playtime stops. Once she bites or scratches you, stand up and don't engage with her. If she keeps jumping on you or trying to bite at your legs/feet, walk away. If she follows, go into another room and shut the door behind you. Wait for a couple of minutes, then return and start playing again. If she bites again, repeat the process. Since she's already developed a habit of biting, it's probably going to be a little while before you see an improvement. Stick with the training!
Even when we go to pet her on her forehead she does not seem too comfortable and ends up trying to 'shove' our hands away.
A lot of dogs don't like being pet on their face or top of the head. Try to stick to petting her behind the ears, under the chin, and on the sides of her body. See if that helps. You might also want to mention this to your vet. Shying away from having the head touched can be a sign of some medical issues.
We are also scared to leave her unleashed when we are asleep as she tends to jump on us and start biting/clawing.
Are you crate training her? She should probably be crated at night until you can get control over the biting/clawing issue. I don't think it's a good idea to leave her on a leash while you are sleeping. She could get tangled up in the leash and hurt herself.
I hope this helps. It's a tricky situation, but you are far from the only people who have had to deal with it. Good luck!