Mechanic's lien

If the property is the owner's homestead (meaning that the owner owns the property and lives there) then your contract with the owner would have to satisfy the requirements of Texas Property Code sections 53.254, et seq., which requires specified homestead lien warnings, signing by husband and wife, and recordation in the county property records. 

If your contract did not comply with homestead lien statutory requirements, then no contractor or subcontractor or supplier could file a valid mechanic's lien against the owner's homestead.

You really should retain a construction attorney to review and evaluate your legal position based on the contract and pertinent documents. The right to be entitled to file a mechanic's lien is set out in Texas Property Code Chapter 53, and you really need to make sure that if your subcontractor filed a lien, your subcontractor has properly and appropriately done so.

Filing an invalid lien could subject your subcontractor to liability under the Texas Fraudulent Lien Act, and your subcontractor could be liable for statutory damages of $10,000, or actual damages, whichever is greater, plus attorney's fees. 

You are responsible to the owner (assuming that you have been paid) for resolving/removing your subcontractor's lien. So, consider writing a letter by certified mail to your subcontractor to point out that the lien is invalid and violates the Texas Fraudulent Lien Act. When I write such a letter for a client, I include a Release of Lien filled out with the pertinent details to make it more convenient for the matter to resolve.

Good luck.