If they are to the point where they are vying as to who is going to be the top dog, believe me it will only get worse. And there are few alternatives as to what to do about it if it is at that point.
1) let them work it out between themselves. Most dog "fights" (like 85% or maybe even more) never draw blood, or if they do it's just a surface wound. It looks very intense and agressive, but it's mostly scrapping and not actual fighting.
2) Keep them separated from each other or only have them together under extreme supervision.
3) Try some serious training with a professional that has experience with dog aggression and dominance issues
4) Worst case scenario. Find one of them a home where they can be the alpha dog with no challenges by other canines.
If they both have dominant or alpha personalities, I'm not sure if things will get better until they figure out where they stand. Lacy does not want to give up her position as the alpha dog in the house. Kali is getting older and if it's true that she may be the more dominant of the two, she is now at the age where she may be challenging Lacy without you noticing the subtle signs. That alone may be setting Lacy off. If they do get into a serious fight, I'm guessing its going to be Lacy that will be injured, just b/c she is smaller and Kali has a thicker coat to protect her.
Now as for her sudden human aggression issues, I'm going to take a wild stab and say it may still have to do with her being displaced or being on her way to being displaced as the alpha dog. She may be trying to find her new place, and is trying to work her way up the ladder by challenging those alpha to her, the humans. She does not want to be on the bottom of the totem pole and is therefore acting out a bit.