Can I, or should I amend the return filed already as MFS to change the return as single?

[SunnySpring]

A client who has filed already her MFS return has just found out that her divorce was finalized before the end of previous year (2020), and now she asks if she needs to amend the already filed return to change the filing status from MFS to Single.  Should she, or could she, amend the MFS return to change the filing status only?

[TylorValdez1]

The client's marital status as of December 31 of each year controls your filing status for that entire year. They will need to amend the return and change the status to single.