welcome to healthcaremagic
how long is she suffering from this? It may be Acute retention of urine .It may be be caused by nerve
, infection, or medications (including anticholinergics, antidepressants, COX-2 inhibitors, amphetamines
Diagnosis and/or treatment may require use of a catheter.
I suggest you to consult doctor
if the symptoms continue more than 24hr for further investigation and management