Hi K.,
First I want to say, I'm so sorry your young daughter is going through this terrible infection / illness.
When reading your story, I thought of my daughter and wanted to share with you what happened to her and maybe this information may or may not be of use to you and your doctor to help your daughter.
My daughter at the age of 17 had developed 2 kidney stones trapped on one of kidneys which were so huge and painful she was hospitalized and had a stent inserted to move the stone off of her kidney.
To make a long story short, numerous tests were done and it turned out that my daughter had an over active Para thyroid which produced too much calcium in her system and in turn they created the kidney stones, and infectioln. She had two surgeries, one to blast the kidney stones away because they were too big to pass and then when she got stronger, she had her Para thyroid removed by a head and neck surgeon. My daughter has a scar at the base of her neck but over time it had almost vanished.
The issue of the strong antibiotics is also an alarming issue; my daughter was on Cipro and other strong antibiotics for months while dealing with the kidney stones, she ended up getting yeast infections. I called her doctor and told him she was going to stop taking them for awhile.
I know that taking strong antibiotics for long periods of time can lead to other bad health issues. And your daughter is so young.
Maybe your daughter needs to see another specialist, because there maybe another underlying issue that is creating these infections.
I wish the best for your daughter.