I have a client that is just now filing his 2019 return. His wife, unbeknownst to him, filed a 2019 return on her own. It is unclear what status she filed as, but suspect MFS or Single. She did not claim their child. She did not even have any income. Presumably, she filed to get her stimulus check. The taxpayer has not filed his own return yet. How do I go about filing a MFJ return for them both?