I want to injure my main character, not badly enough to kill her, yet strong enough to keep her in the hospital for 1-2 weeks, with full recovery. I was thinking maybe a stab wound? If you have any suggestions, they're much appreciated
An acute medical problem with a full recovery...Have you considered a bacterial or a viral agent, like meningitis, or a staph infection? Those have the potential to put people down hard with a reasonable 1-2 week recovery time depending on severity.
Nervous breakdown. Which gives you a reason to be really cruel to the MC for a long time until it happens.
You should make the injury pertain to the reason you need to keep her in the hospital for two weeks! Like, if she's a cocky son-of-a-bitch and she thought she could take on the world, and values her freedom, have her break a leg so she recognizes her own mortality. Or if she thinks she's at one with herself, that she's healthy and has no problems, have her suddenly need a kidney transplant or something. This sounds like a great spot for her to hit a low note in the story! Contrive the crap out of it!!