Since the question seems to be orientated towards if we were both alive and she needed something, it would depend what it is. Blood, yes. Organ, probably not. I'm an organ donor (when I'm dead, ya know), but I don't think it's fair to give something to her that you wouldn't give anyone else. But that's just my personal opinion.
I absolutely won't ever give one of my kidneys to anyone unless I really, really thought about it for days and the person was really, really close to me like a relative or best friend. I heard a story about how someone (who I'm pretty sure was in my family - I think my mom was the one to tell me) once donated a kidney to a relative that was dying, and then a few months later their (the donor's) remaining kidney went bad. They ended up dying and the person they gave their other kidney to is still in great health. And the donor was like in their early 30s and the receiver was in their late 50s. I won't ever give my kidney to someone for fear that this will happen.
Especially since my family has genetic kidney failure...