Because she was a governor, you realize that ex presidents are still introduced as "President." Not a fan of hers but when you held a title in office it's customary to be addressed by that title.
For the same reason that Clinton is still addressed as "President Clinton." Its just an honorific that you keep after you do something. Same thing happens with military rank when you leave the service if you want it.
For the same reason that Clinton is still addressed as "President Clinton." Its just an honorific that you keep after you do something. Same thing happens with military rank when you leave the service if you want it.