Parenting siblings can be a gift and a curse at the same time. Did you know that on average siblings argue every 10 minutes? Did you know it is inevitable that you will favor one sibling over the other? Did you know that the more you try to create equality the less they perceive fair and equal treatment? Did you know that 1 in 3 siblings experience some sort of abuse?
I don’t throw these stats out to take hope about your family away, rather to get your focus in a more helpful and productive state. Stop putting your time, effort, and energy into equality and put into teaching siblings to protect, care for, and support each other. Although there are times that stepping in is imperative, stop refereeing every conflict of their relationship. In fact try to set a boundary on involving yourself at all in their petty and frequent arguments. It is more helpful to put boundaries on their reactions to conflict in a general sense. In other words stop trying to figure out who started it and simply set boundaries on things like yelling, cussing, hitting, and name calling in a general sense.
The most important focus has to be on recognizing, admitting to, and stopping any bullying going on in the home. This is not always being done by the older, bigger, male siblings. Often the abuse (especially emotional) can be coming from the smaller sibling or the female sibling. If there is any abuse psychologically or physically going on do what you can to stop it and to protect the victim. Ask for help from an expert and do not try to deal with it alone.