Now that she's been well for several years, she can eat those foods again. Another good reference is Anne Frye's Understanding Lab Work in the Childbearing Year and Susan Weed's Wise Woman Herbal for the Childbearing Year - although they both recommend cranberry juice, I think if all three were read and course of treatment could be worked out for an individual patient that would work. My understanding of the cranberry juice thing is that it would take gallons of it to actually make your urine more acidic. If they've got no place to hang out they are toast. That would be the bacteria-fighting chemical known as hippuric acid.
Acidity really has nothing to do with cranberry's effectiveness.
Cranberry prevents the UTI germs from adhering to the lining of the urinary tract. It also has a very high vitamin C content which nourishes the immune system. You can still drink lots of water but don't need the large volume of sugar. I don't think its that the cranberries kill the bacteria. I think it changes the PH of the urine and helps to resist the bacteria.