Someone I love dearly came home in 2006 after a 15 month tour. It was a tough 15 months with him away. Living in fear that you're going to get that knock on your door is never easy. But, as my friend said, he wanted the T-shirt.
Your SIL's a lucky guy to have everyone who loves him supporting him. My best to your SIL from boots on ground until he's back on U.S. soil. I'll keep him and our other servicemen and women in my prayers.
Your daughter deserves some extra love and attention while he's gone.
Think up some great care packages to send to him!