firstly, this doesnt sound like handler agression...this sounds like puppy domnance...and frustration
this dog was taken form its mother too early, puppies legally should be left with their mother untill 8 weeks of age minimum, but studies have shown, even for LGDS its actually better to leave puppy wiht mother and siblings untill 10-12 weks of age as theres alot of critical learning down betwen 6 and 12 weeks...
primarily...
BITE INHIBITION!
unfortunatly, being taken from mother and siblings at 6 weeks of age this puppy hasnt had any formal training from its mother in bite inhibition...aka "doggy manners" so now you get to start from square one with a uppy whod essentially eb considered "the slow kid" its not that the dog is broken or a lost cause or automatically going to be evil when it matures....its that this dog has missed a critical learning period with its CANINE family...so now you have to fill in that gap as best as you can as a human.
now my personal training belifs are we are not dogs, puppies know we are not dogs and trying to disiplin how yout THINK a mothr dog would issnt going to work...
ive used my methods on dogs from chihuahuas to lgd's to wolf hybrids and yes these methods have worked with large exotics...primarily lions, tigers, hyena and african painted dog...
firstly...mother would never scruff and shake, EVER...dogs shake to KILL, its never a disiplinary method, do you realy want to teach a dog with the potential to kill someone that humans are trying to kill it? in my opinion no...not even remotly the goal, youll likely end up with a very insecure and very dangerous adult with those methods.
scruffing should be a short sharp shock, you scruff quick, a quick "bite" and then let go. its like a spank on a child, whats more effective, one quick sudden shock or sitting there beating the snot out of them?!
now for mouthing...i typically practice the "end game" method...in a normal family dynamic if puppies play too rough, the game is ended with a yelp and no interaction...puppies crave attention and by ending the gam puppy leanrs pretty quickly, when i bite my brother or sister or mommy...all fun stops...
being that we are human i dont allow ANY teeth on skin EVER...were too fragile a species and accidents can happen, so when game turns into nipping, the game stops, make a sudden loud sound, a yelp, a strong NO, something, stand up cross your arms and turn away.
once puppy stops trying offer puppy a toy they CAN put their teeth on.
if puppy continues trying to be moughty (pant legs jumping ect) remove puppy from the situation into a "time out" a crate, stall ect, keep it short though, like a toddler they have the attention span of a peanut and if you leave puppy sitting there for 30 mins itll have NO lcue why its there anymore.
my max is 10 mins for time outs, but with pups i do 2-5 mins. let them calm down and then resume play with dog safe toys.
teeth start to try for flesh, repeat.
puppy will very quickly learn that teeth on people skin = ALL STOP...
you MUST be consistent.
now pups with dominant personalites, like yours sounds ot have often get frustrated when these games get stopped...this often happens whn theyve been alloowed to be mouthy for a few mins then suddenly the game is over, they dont understand eactly why the game stopped (this is why you must do it imediatly if teeth touch skin every time) and they get frustrated.
there also testing boundries...are you "mommy" or are you "sibling" mommas responce to that kind of agression would be to get big and tall, very loud and loom OVER puppy, puppy would typically offer a roll displaying its belly, if not dont ROLL the puppy but encorage puppy to show tummy as often as possible. dogs NEVER forc eachother over unless they intend to kill the one they are rolling so again we go back to the...do you realy want a dog that thinks your trying to kill it?!
youll also want to work on the dominance on a daily basis, make her work for her food, feed her by hand, she needs to knwo YOU provide the food and she has no rights to it unless you let her. you walk ahead of her, always go through doors and gates before her, make her back up or get out of YOUR way never go around her, make her go around you. simply establishing yourself as top dog in the pack
also remember shes a 9week old puppy with more energy than tigger on speed! get her moving, running, playing, find toys she can enjoy and get that puppy moving...a tired puppy is a calm puppy!
also start her on basic obedience, there never too young to learn sit, down, stay, building her confidence and excersizing her mentally will help quell the excess energy that often leads to frustration and mouthyness...
this much is very 100% certain though, YOU need to establish dominance, you dont need ot be rough or physical to do so, simply making her sit before she gets her food, or making her move out of your way are simple daily acts that make a world of difference.
good luck with your baby, and remember that..she is still a BABY!