Start with the recorded deed to see whose names are listed as owners. Being married, separated, or divorced by itself does not answer every signing question. A divorce decree or another court order about the house may affect whether or how it can be sold.
The title company reviews the deed and any papers that apply to the sale, then confirms which signatures and closing documents it needs. A Tennessee family-law attorney can explain what an order means for your situation. You can talk with us while those documents are being reviewed; you do not need to have every answer before you call.