Can you have that be your "hook" and then tie it in somehow to the "why medicine" question? I touched on some family stuff too but found a way to tie it in to the larger theme of the PS.
One other thing I heard discussed at a pre-med conference is that you should make sure that you are willing to talk about things you put in your PS at your interview. If it's sensitive or you can't remain composed while discussing it, you should leave it out.