I'm sorry, but I am a wife, daughter, granddaughter, great-granddaughter, sister, and more of military men...not one of them would EVER expect to not go into a war zone because they were the only son. They all joined VOLUNTARILY to serve their country, which means going to war if needed.
Everyone who has a loved one in a war zone is worried - that means THOUSANDS of people are worried every second of every day. My parents didn't sleep for the 2 years my brother was deployed in Iraq (Army Infantry). My mom didn't sleep the multiple tours my dad did during Dessert Storm. I'm sure my grandmother was very worried for my grandfather while he served in Vietman. It's part of what comes with the territory.
She needs to know that her husband is trained to do what he needs to do and will do his very best to come home safely, it's what he wants too.
I'm also confused if this is his first time on a carrier? Granted most of the men in my life are Navy, which means lots of time on ships, but they routinley go out for longer than 6 months at a time. She really needs to get in to a support group of military spouses/families.