Thanks for deferring to me Chrisanne!

How often is this really happening? Once a day? Once every two days? Several times a day? It sounds to me like what is happening is what happens when most pits reach that age...actual adulthood. Normally, it doesn't get any worse than what you are currently experiencing with dogs of opposite sex, but when both dogs are the same sex, they often need to be in different homes. However, pits of the same sex (females only) will often get over it quickly espcially if they are littermates.
Kali and Orion often do this, sometimes its a couple of times a day, sometimes it's only 2 or 3 times a week, and sometimes they go for a good long while without any episodes. As long as you can curb it with your voice, you are doing good. With Kali and Orion "Enough" works for us. What I've noticed with my two, is that Orion will want to play, Kali doesn't and he will badger her until she reacts and it will escalade. There is a lot of noise...growling, barking, snarling, but neither one is really doing any biting or damage to the other. Kali is telling him to "leave her alone". This usually happens in the summer months when it is hot and sticky and she just doesn't want to be bothered with playing...(he's too dumb to realize it's too hot for all that)
As far as the incident with the toys...well, we get that too. It sometimes seems Orion only wants whatever Kali has at the moment. Often she'll let him have it and go get something else. He then wants that something else of course. What seems to be going on there, is nothing more than typical sibling rivalry like what children do. As far as pushing the toy in the other one's face, she is daring the other one to take it. She's saying "go ahead and take my toy, see what happens" She's telling the other dog that it is "hers" and not to touch it.
At this point, controlling it with your voice and as long as they aren't breaking skin, they should be okay. If as the weather gets cooler, they should ease up on it and if not, well, you should just cross that bridge when you come to it. For now, I would suggest feeding them in separate rooms to help ease tentions and not offer any new toys at the moment. Be consistent with treats, pick one to ALWAYS get their treat first and stick to that. I know it's frusterating and difficult, but don't be afraid of them, they aren't upset with you, just annoyed by each other. Control is key and you have it with your voice. At this point, I honestly wouldn't worry about it too much unless it escalades into something you cannot control with your voice or stop by throwing a pillow at them (another good attention getter) My advice is also, pay a little extra attention to the dominant one, offer her treats first and such. It's not really rewarding bad behavior, but using precaution to avoid problems. I tell people with bully breeds, you don't have to use "extra" precautions, just different ones.
If you have any questions, concerns, vents or remarks, please feel free to contact me whenever...living with these guys is rewarding and frusterating all at the same time, but so worth the effort

Believe me Sweetie, it's not you or anything you did wrong, just normal sibling rivalry behavior and one trying to establish herself as being above the other...they'll work it out. Your a great bully mom! So don't beat yourself up about it and tell your Hubby to just tell them to knock it off...he'll soon learn too that they are just being brats.