This may not seem like much but my two girls, ages 12 and 7, cannot stand each other. Every car trip is a headache. Even 5 minutes is an argument or consistent name calling. I allowed them to each pick a movie and then we settled in with our food for the night. The surprising thing is that the oldest actually sat through (and liked) the movie that the younger one picked out. AND they didn't argue the whole time. Almost four straight hours with no complaining. It was wonderful.
The deduction, other than loving having time with my girls, is that girls/boys night will become a regular monthly thing. While regular family nights are important, getting two siblings of the same sex to bond on their own time is essential also. This can be difficult for those with families larger than average family of four.
Set aside some time to divide and conquer sibling rivalry so that you can come together as a whole at a later time. Get creative, it doesn't have to cost a bunch of money. Our Redbox and dinner was less than $10. Get to know your kids again and help them learn about each other.
Most of all, HAVE FUN!!
What are your favorite things to do with your kids?