My daughter is one five weeks old, what are the signs if her soft spot being hit or head trauma? My boyfriends sister dropped my iPhone 4s on her head

Don't worry. Unless she threw it with intentional hard force, just dropping an object the weight of an I-phone on her head will do nothing more than cause a little bruise if anything. Remember, 5 weeks ago her head squeezed together through a birth canal. It's more resilient than you think!