No...She DOES die if Kirk is not there...
If your saying there's no Kirk there (I suppose your saying this because the Enterprise never goes to the Guardian Planet), then there is also no McCoy there to prevent her from getting killed -- most likely by the truck.
- She originally died in the unaltered timeline probably because she got hit by a truck (although we never found out for sure).
- She ended up living in the altered timeline because McCoy did
something to save her (again, it most likely had something to do with that truck).
- Kirk restored the timeline by (presumadly) preventing McCoy from saving her from the "inevitable" truck accident.
I have a headache.