My 14-year-old daughter says her tongue is hurting on both sides. She says its sore and it feels like she burned it on both sides of her tongue but she didn't. By the way she has braces if that is a factor in any way.

It most likely has everything to do with the braces. :(
I had braces twenty something years ago and I can remember almost having jagged edges after they were tightened. Its very possible there are exposed wires or some pointy wires. Some salt water rinsing and the wax will really help. The tongue rests on the inside of the teeth and brushes up against the hardware whether lose or poking. Line the inside with wax for a few days and it will help the irritation. Good Luck and SMILE!!