Sounds like my early experience with my WCS puppy, Ivy! I promise she will grow out of it and it will get better as long as you're consistent in how you respond.
I managed to stop the biting and clothes pulling by redirecting her to a toy with lots of praise when she chooses it instead of my sleeve! If that didn't work, I would say 'ouch' and turn my back to her and cross my arms. When she sat or stopped jumping at me, I would start playing with her again. If she didn't calm down or stop nipping, I would leave the room for a few minutes and then come back and resume play/cuddles. After a few weeks of this, she learned that biting or clothes pulling meant the end of our play or interaction and soon stopped doing it.
Sometimes, nothing worked as she was too overstimulated/tired and I had to pick her up pop her in her pen/crate for an enforced nap.
I wouldn't worry about her behaving a bit differently with you. The biting and nipping is all normal puppy play so it's actually a compliment that you're her favourite to play with!
Ivy definitely monkeys me around more than my hubby, but it could be because I spend more time with her. I watched her earlier follow him calmly into the garden and do her 'business' on command, then trot back in and stop on the mat for him to dry her paws. This is absolutely NOT what happens when I take her for a toilet break!! But then, she normally chooses to sleep on my lap in the evening so...
Good luck with your new pup! I remember 12 weeks being a trying (and tiring) time, but it does get easier I promise!