Hi welcome to Health care magic forum. I suppose the infection must be of kidneys rather than uti. I advise you to consult a nephrologist
for diagnosis and treatment. He may need to get c/s of urine, besides other routine tests for confermation of the condition.
Besides i advise you some diet recomendations for her as give her green leafy vegetables, pulses, sprouts, milk, egg, meat, sea foods, fruits, juices, and dry fruits to build up blood, general health and resistance to such infections.
Some habbits she must be taught, as washing after defeacation from behind for such cases. And to pass urine as frequently as possible and not to hold for long time. Wishing for a quick recovery and thanks for calling.