What was holmes' provisional theory about the people in the cottage? How accurate was he?

The facts ,as I read them ,are something like this:this woman was married in America her husband contracted some diseases.she fled For him , returned to England,changed her name ,and started her life afresh. She had been married three years ,and believe that her position was secure-having shown her husband the death certificate of some man whose name she had assumed-when suddenly ,her whereabouts was discovered by her first husband,or by some unscrupulous woman who had attached herself to him.