Welcome! Thank you for your question.
Generally her second husband would file a married filing jointly income tax return for the full year of her death. Here estate would have to file income tax returns for the year following her death. It is beneficial to her husband to file a joint return because he gets the benefit of the higher exemptions.
With that said, technically if he does not want to file a joint return, you would be responsible to file an estate income tax return for the income that she earns from the date of her death forward to the date that he estate is closed.
I cannot provide you with legal advise. I have provided you with information about the law related to your question. My answer, and any information that you find online, should not take the place of having a consultation with a lawyer in your area to advise you regarding your specific issues.
Please show your appreciation for my candid, accurate information by clicking VERY INFORMATIVE, OR the OR and positive feedback. You should only rate me if you are satisfied with the information I provided you. If you cannot rate me GREAT please do not rate. Give me a chance to make it right by clicking REPLY TO EXPERT.
I appreciate your question and repeat customers. You can request me by beginning your question with "Dear XXXXX..."