Hi
Welcome to the MedHelp forum!
There is no way you can help except take her to doctor. The only thing you can do is press at the site of pain and see if it increases the pain. Such a pain is usually muscular or due to costochondritis. This will respond to painkillers and heat pack. If the pain is from inside, then it cab be due to heart causes, pleurisy, acidity and lung tumors. Take care!
If she's crying then its painful for her. If I couldn't get her to go to the doctor's office or walk-in clinic, I would call her an abulance. (It's expensive, but it usually gets the job done.)
is it a "not able to breath pain"?
get her to calm down...give her tylenol (no motrin)
have her lie down in a quiet room with an ice pack on her chest...
if she starts to have trouble breathing or other serious issue, tell her to suck it up "ur gonna take her to the doctor whether she likes it or not" tell her not be a baby and take care of her health.
There really is no way you can help her except to really encourage her to see a doctor. From what you have posted, is seems to me that she should see one as soon as possible.