A very kind guest recently remarked on how well the Zoomlians get along. The fact is that the Zoomlians don't always get along! But still, "They really love each other." is an awfully nice thing to hear about your kids, and I know it's true.
I've been hesitant to write this post because my kids aren't perfect and our parenting isn't perfect, but I would like to say two things that have worked for us.
1 We actively teach our kids to love each other. Most of it is "caught" instead of "taught," of course, but we also teach it. A big part of that is pointing out any loving behavior and saying, "Oh, look how much she loves you! Wasn't that a nice thing?" (We actually start that when they are babies- any smile is proof of affection!) Another is using it as a starting point when there are disagreements or arguments: "I know you two love each other, so I don't think you are trying to hurt each others feelings. Can you figure out what is going on here/ a good way to fix it so it's fair to both of you?"
2 We try to give and ask for loving behavior. No sarcasm allowed. Apologies when mess ups happen. When we are having a rough day, explaining it and asking for mercy. This morning I woke the kids up and told them, "I was up 7 times last night and I'm really tired this morning. Could you all just get ready without me asking over and over? " They gave me hugs and Zorg gave me a backrub (!) and all zipped around and helped with breakfast. I don't think I've ever asked for help as a personal favor and not had the kids rise to the occasion (I have, of course, demanded help and not gotten it!). I think there is something important about kids being able to give and not be on the receiving end all the time.