I'm a single mom and I know siblings fight. Mine didn't fight much- they truly cared for each other. I tribute that to the love of God but, I treated them as individual human beings and not by their gender (like some parents say; well he's a boy what do you expect and vice-versa). If my kids were fighting I had them sit facing each other on the couch and they had to say something nice to each other (back and forth). They would begin laughing and say goofy things to each other. Then any time they were in time out I had them talk about the situation and how it could be solved and how not to do it again and how it made them feel. The key is one person has the floor to talk the other must listen. This taught them communication skills, respect, etc., and made them responsible for their actions. I look at people as being good but it is their actions that make them bad or good...We must be responsible for our actions which are reactions to others actions.