Some time ago I wrote an article called, Zestiment – read the fine print. This is a great video that talks about that how the inaccuracy affected this owner very negatively. View it for yourself & remember, Zillow gets their information from public sources and Texas is a non-disclosure state. That means it is even more likely to be inaccurate.
When in doubt contact a Texas Realtor or Appraiser to get a more accurate evaluation under current market conditions.