Is this a problem or phase?

I have to husky puppies that come from the same litter pup a went with my sis for a few months but I took her back after realizing my sis...isn’t suited for pets. (Probably the nicest way I could put it) so after a few months and a lot of begging on my part Pup a came back to live with me. Pup a & b got along in the 1st few month of their life by since pup a has return she’s been way more aggressive. She gets in the trash can outside and I thought it was cause she was bored so I started taking both pups out more and playing with them more and bringing toys and treats and the whole shabang. But the thing is she’s still very aggressive. Not to humans but other dogs, specifically pup b. But she means to our chihuahua sometimes as well pup b and chihuahua get along fine and pup a does to but sometimes she’ll go up to our chihuahua and literally just push him over. (He’s a old dog so it’s very concerning when he falls down) but back to pup a & b. Pup a will start fights with pup b out of nowhere and at first I ignored it cause their pups and that’s what pups do. But pup a...seems to really try to hurt pup b. Pup b will be begin to cry and pup a is still going at it until I call her. And then pup b will go eat some food from the his dog bowl and a few moments go by and pup a is drinking water when she starts growling at him and attacking him. And then theres the toys. I have given both dogs numerous toys and pup a hogs them all. Like pup b has a favorite toy so even with all the toys I give them he really just wants the one specific one. But pup a starts fighting him for it. So to ease things up I give pup a, pup b’s fav toy and show him another one. And as soon as he starts to take it pup a drops the toy and attacks him. I’ve literally sat them both down on opposite sides of the room given pup a all the toys except pup b fav stood away from both of them and just watched what happens. Pup b is sooo content with his fav toy while pup a legit just sits there watching pup b play. Surrounded by al the toys she just watches pup b. And whenever I try to leave the room she rushes pup b and tries to take the toy. Sometimes she doesn’t even try to take the toy she just rushes pup b. Pup b is older and pup a was the runt of the litter so in comparison pup b is way bigger than pup a and could probably take her. The thing is pup b is one big teddy bear. Legit just wants to cuddle everyone. We have a neighbor who’s dog is super mean and bit pup b once and pup b still tries to play with it. Another dog tried to fight pup b and he legit just put his paw out to not let the dog bit his face. I worry about him sometimes...but I’m getting off track. The point is pup a is really mean to pup b to the point where he scared of her. He doesn’t even want to touch his favorite toy cause he’s afraid she’s rush him. I’ve seen just slowly try to sneak his toy while watching her. When he’s eating pup a will go over to drink some water and just all attack him. I’ve got no clue what to do. They were doing fine and all of a sudden she’s like this. I’m so concerned for both pups. I just wanna be a good dog mom but I don’t know what to do. Does this mean pup a just isn’t fond of other dogs? Or just doesn't like her brother? Is it the heat that’s getting to her? Is this the effects of the parenting my sis did? Really what I’m trying to ask is this something I should be concern about or is this just a puppy thing that’ll phase out?