First off, I am not a lawyer and this is not legal advice. If you want legal advice, seek an attorney.
I'm gonna break this down so I can try to answer it more thoroughly.
i understand you cant carry at or around a school.
Assuming you have a permit, you can carry around a school as you please. 724.4A, the weapons free zone provision, merely doubles the fine for a public offense involving a firearm within 1000ft of a school or public park. It does not prohibit the carry of a firearm within the so-called Weapons Free Zone.
the building she teaches in isnt funded by tax dollars or considered a school
If you were sure it wasn't considered a school you wouldn't be asking this question. What grade levels are we talking about? Pre-K, K-12, Post Secondary? Is the building she teaches at being leased by the school for instructional purposes? That would make it a school.
so am i allowed to carry in this building if i were to visit her there for lunch or something?
That depends on whether the location is considered a school. If it is there is an exception for 724.4B for "A person who has been specifically authorized by the school to go armed, carry, or transport a firearm on the school grounds, including for purposes of conducting an instructional program regarding firearms." Good luck with that. If it isn't then private property rights still apply. If someone asks you to leave, you must, but if you take "concealed means concealed" seriously, it wouldn't be a problem.
school events happening off of school grounds. if you happen to be out and about (carrying) and theres this school event going on at the mall or something. do you have to be 3000 feet away from the school event?
This one is interesting. A mall, literally, being a place that is open to the public and with an implied invitation to the public would be a hard argument to press it was a school, even if there is a school related event going on at the time. Other locations, such as a football stadium or a baseball field used and shared by a school district/area education agency would most likely fall under the definition of a school.
Find out who signs your gf's paychecks or who her boss is. Find out what authorizes their position(assuming it's public). That should give you a good starting point to find out what you need to know. As of right now, I'd say keep your gun case in your vehicle, park off the grounds of the location, unload and encase it so that you are under exceptions e/f:
A person who for any lawful purpose carries an unloaded pistol, revolver, or other dangerous weapon inside a closed and fastened container or securely wrapped package which is too large to be concealed on the person.
A person who for any lawful purpose carries or transports an unloaded pistol or revolver in a vehicle inside a closed and fastened container or securely wrapped package which is too large to be concealed on the person or inside a cargo or luggage compartment where the pistol or revolver will not be readily accessible to any person riding in the vehicle or common carrier.
It is a Class D Felony to carry on the grounds of a school in violation of 724.4B. You will want to make darned sure that it is not a school or that you have permission before risking anything.