If the property became your husband's on his father's death and your husband's will leaves the property to you, then the property is yours. If your husband died without a will, it becomes much more complicated because his inherited property is separate property.
I'm sorry for the loss of your husband. I recommend consulting with an estates attorney privately as there are some specific questions/answers needed to evaluate which best fits your scenario and advise appropriately. I do not suggest anyone share private information in a forum.
First question I would have is - was his father's will ever probated? Second, does he have children from a previous to your marriage? There are many more as well. Best wishes.
If the property was left to your husband in a valid Will, it became your husband's property. Your mother-in-law has no interest in it.
If your husband died with a valid Will, the property passes as the Will states.
If your husband died without a valid Will, the property passes under the Texas Rules of Descent. You can find pie charts of these on the website of the Travis County Probate Court., Inheritances, including inherited real property, are not community property in Texas. They are separate property. If your husband has children from a previous marriage, they, as well as you, may have an interest in the property.
Either way, you need to hire a probate lawyer to probate your husband's estate. Title companies will not insure title without a "clear chain."