Cashing in stock

My husband bought stock in a particular company throughout the 90’s before he met and married his now ex-wife in 2000. He invested small amounts of money after they were married into more stock but most of the investment was made prior to their marriage. We recently found out after being audited by the IRS that she cashed out the stock in 2005 after they had been legally separated since January 2004. My question is, since the investment was made by him, with his money, before they were married did she have the right to sell the stock without his knowledge or consent and further more keep the money all for herself?

The money was part separate and part marital. She was not entitled to all of the money.