Start with the recorded deed: it shows whose names are on the property record. If ownership changed later, or an agreement or court order addresses the house, those papers matter too. If both names appear on the deed, do not assume one person can sign for the other.
The closing title company checks the deed, later ownership documents, required signatures, and any court papers that affect the sale. A Vermont attorney can explain what an agreement or order means for your situation. You can start the house-sale conversation while those questions are being checked.
Hartford is a town in Windsor County, Vermont. The Town Clerk is a local starting point for recorded deed and land-record questions; a record search does not replace the title company's review of the documents needed for this sale.