Where is the exact location of the pain on abdomen?
Has she bloating, gas, diarrhea, fever, heartburn?
What are her medicine, apart from which you mentioned?
Any significant past medical history?
No bloatig, gas, or diarrhea. slight fever. No heartburn. she is taking no other meds
Just the bladder infection and she has had that before
The vomiting. fever and pain can be due to;
1) Kidney infection; a bladder infection can extend to kidneys. She may need a urine culture which tells about the best antibiotic to be effective against the infection. Nitrofurantoin may not be very effective for the infection.
2) Drug induced gastritis; nitrofurantoin can cause this, which may be responsible for the pain and vomiting. The treatment would entail;
2) Dimenhydrinate (Dramamine) or meclizine hydrochloride (Dramamine Less Drowsy).
If these do help in the vomiting and pain is moderate or severe in intensity, she may need to consult at ER.
Please feel free for your follow up questions.