She's probably cooking dinner, or has gone out with her family.
Her son is 18, I think, and she worries, too.
It's normal for us...my wife routinely calls the boys on the cell phone to make sure they're ok.
We just canceled the cell phone. I'm looking into new plan. That just made it worse. My husband is away so I think I was worried more than normal. I always worry though! :) He just got home, now, Woo Hoo!