What happens in Texas to the entire estate if a spouse dies without a will?

If all of the decedent's descendants are also descendants of the surviving spouse, then the surviving spouse gets everything. If not, then the surviving spouse gets to keep her half of the community property and also gets a life estate in one-third of the decedent's separate real property and 1/3 of the decedent's separate personal property (which includes cash). The surviving spouse also gets the right to live in the homestead for however long she chooses, until she abandons it, but she must pay the interest on the mortgage and taxes with respect to the home. The decedent's children get the rest, and they are responsible for principal reductions on the home mortgage and any insurance.