If premarital property is sold during the marriage for a profit over the original value at the time of marriage, is any part of the sale income considered to be community/marital property?

My husband's family business (him, his sister, and both of his parents) owned property in Texas prior to our marriage. The monetary value of the land at the time of our marriage about 18 years ago was very small, but after our marriage, oil was discovered on the land. After I filed for divorce (it still is not final) in Georgia where we are both currently residents, the land was sold for a huge profit, with each member of the "family business" receiving 1/4 of the proceeds. Is any part of my spouse's profit from this land sale considered community or marital property? I have been advised by one attorney in Texas and another in Georgia that half of my spouse's part, minus his part of the premarital value, is considered mine. My own divorce lawyer does not seem to think so, however he doesn't seem all that sure. How is this situation addressed in Georgia law? Is there a reference that can be cited for my lawyer to look up? There are also three minor children involved, and I have been granted temporary custody and anticipate full custody after the divorce.