LuvABull, no problem.
hhheights...well they don't call female dogs the b-word for nothing.
This is very typical bossy "b" behaviour. I would NOT give her a chance to be bossy, especially with three females you need to run a tight ship if one of them is being extremely dominant, like this girl is. She's still a puppy, you need to watch that she doesn't decide to eliminate one of the other girls when she matures a bit.
I would give her NO
chance to snap. None. Or any other bossy, guardy behaviour. She is with the others under supervision only. If you must give each a bone or treat, she either eats in a crate or you attach a lightweight leash to her and give a firm correction if she goes after someone else's stuff (along with lots of praise for showing restraint and manners!). Remember: everything is yours, even after you've handed it to a dog.
I have had...at least three girls like this, and one male. All three of the girls were to some degree or other, same-sex aggressive. My current JRTx is exactly like this. It's why she lives with three boys.
Who tolerate, and don't mind her being a bossy little thing. I'm very selective about other females I bring into the house though (I do foster dogs.) Because I won't put her in a position where she feles she has to defend her status, therefore no uppity or hyper female fosters.
Funny - JRTx weighs 25 lbs. Boys weigh 110, 85, 60. She rules. LOL. But she knows she must be reasonable about it.
Basically: every chance your new pup gets to snap at, bully or terrorize the resident dogs reinforces her opinion that she is fully entitled to do so. Which is absolutely reasonable from her point of view. (And could turn ugly at some point later.)
But every time she is corrected for being a little b, and praised a TON for acting nice, will reinforce the message that she has to act nicely in order to get positive attention from you, and that you won't tolerate rudeness.
So how you react will determine how mannerly she turns out. If you continue to allow her to be a bully, that's what she'll be. I'd start working on self control exercises - leave it, stay, sit until released....and make it very fun so it's rewarding. Dogs like this can be so fun to train, but trained they must be!