Fiance was given medications that caused her kidneys to be damaged

First,  bear in mind that any recourse is your fiance's alone, not yours, until and unless you are married. Being engaged is not a legally recognized relationship and conveys no rights.
Second, the issue is not merely if she was harmed, but if giving her ibuprofen under those circumstances (based on what the medical care providers knew and reasonably could have known at the time they administered it, and how the balance of risk vs. potential gain stood, since often it is apppropriate to give medications with side effects if the need is great enough). Based on what you write, there is a reasonable chance that this *was* malpractice: you write that other doctors have told you that it was wrong to give her ibuprofen based on her blood pressure, which is something hospitals, etc. monitor--so in that case, they should have known not to go do this. And ibuprofen is not the only choice for pain or inflammation relief, and is generally not a critical medication, meaning that you can generally safely NOT give it if there is a contraindication and give something else. So administering her a non-critical drug when there was reason to think it inappropriate may well be malpractice.
If your fiance has suffered permanent or long-lasting damage with some significant effect on her, then if this was malpractice, she may be entitled to a signficant award. Based on what you write, it would be worthwhile for her to consult with a malpractice attorney (many provide a free initial consultation to evaluate a case; you can confirm this before making the appointment) to explore her options in detail. Good luck.