Its in her back and abdomin. She said it so bad she feels like she has to puke. Her period is not do tell the end of the month. Should bring her in to the er?

I really think that the ER will not provide the best care for cramps. They are not going to be able to give her the attention she needs, especially if it is a busy hospital. Call her doctor first thing in the morning. A good gynecologist would be best and if she doesn't have one, maybe her doctor can refer her.
Mid-month cramping is actually common, but we aren't there to talk to her. There are so many possibilities.

She should probably take some Ibuprofen or Advil for the cramping, and maybe a warm bath. Sometimes ovulation can hurt like that (speaking from experience!) and that occurs about a week before the period is supposed to start.

Try Omega 3, B 1, 300 to 600 mg Calcium, 250 to 300 mg Magnesium, Fennel, Black cohosh, brewed teas and fruit juices.