If I bought my house before I was married, and I decide to sell it is my wife entitled to half the profits

It depends on the specifics, but as you describe it, not generally. She may be entitled to some reimbursement if community property funds were used to pay for improvements or repairs on the house, but since you bought it prior to marriage, it would be considered separate property and not something she'd be entitled to half of in the event of a divorce.   The above is assuming that when you say you bought the house prior to marriage, you mean you paid it off completely. If you purchased it prior to marriage but have been paying the mortgage while married, then you've almost certainly been using community property to make those payments (in Texas, income from your work while you're married is considered community property). In that case, she may be entitled to a significant chunk of the equity you have in the house.