5% owner of S- corp widow calls stock

I live in Georgia and have been working for six years for a promotional agency in Georgia in which I accumulated stock as an incentive. The stock was given to me. The majority share holder died in an accident and his widow decides to "call" my stock shortly before selling the company. Are there rules stipulating certain circumstances i.e. recievership etc. or can they just call the stock arbitraily, thus paying me nothing because it was given to me? The shares are valued at about $80,000.

I have been appointed acting president of the company until the sale of the company is final.

The stock agreement is very ambiguos and seems open to anyone's interpretation. Please advise if there are any regulations that govern calling stock.