When my second baby was born, "Is his older sister jealous?" was the most frequent question I got. Relatives, friends, and random strangers on the street all wanted to know the answer to this. When I answered that no, my older child didn't seem at all jealous of the new baby, people wanted to know how we'd prevented jealousy. A friend of mine went out of her way to buy her older son "any gift at all, whatever you want" when she was pregnant with his little sister.
My friend's son requested a bulldozer, and this is exactly what he was given on the very same day my friend left the hospital with her new baby after labor and delivery, as a "gift from the baby for her older brother". It was a ploy to prevent jealousy and sibling rivalry. But is jealousy really so natural that we should be that interested in preventing it?
In my experience, children adapt very well to new situations and usually love babies. It is when we don't pay any attention to them because we're busy with a newborn (possibly a newborn crying!) baby all the time that problems can arise. Making older children feel loved and included, and secure in their place in the family is the best bet for preventing jealousy. Isn't that something that ought top come naturally within any family?
If you area little too exhausted to play rough games with your kids, they will probably understand. There are other things you can do to make your children feel special and loved., like snuggling up in bed together and reading a nice book!