If I personally wrote a check for my half of a building that my partner and I put our business in, can she tell me who I can or can't sell my half of the building to?
The issue isn't who wrote the check--it's who owns the building.
If you own it solely, you can decide what to do. If she owns it solely, you have no say. If you both own it, you have to agree on what to do, or else you can bring a legal action seeking a court order for "partition"--that is, when the owners of a property cannot decide on what to do, the court can order the building sold and the proceeds divided between them. If the business owns it (that is, if the business is LLC or corporation and the LLC or corp. is the building's owner), then the business decides what to do with it. That means you then have to look to ownership interests in the business, it's governance (e.g. operating documents), etc. to see who can make the decision as to what the business should do.
So title, not who provided the money, is the key issue here.