@manojamk , The issue about your wife being a US resident and therefore being able to file jointly is complicated by the fact that all the rules and articulation by the IRS is for a Non-Resident Alien to be treated as a resident for tax purposes, the alien has to be married to a US person ( Citizen/Resident--Green Card / Resident for tax purposes )-- what is not clear here is what does "married to a US person mean " --- the cause of this is because at the time of filing the original 2019 return and at the end of the 2019 , while you were married but you were a Non-Resident Alien. However, once you amend your return, you will be retrospectively considered a Resident for Tax purposes. Thus the question becomes whether your wife can still be considered married to a US Person ( Resident for Tax purposes ) retrospectively. I suspect that IRS generally will accept that the contention that your wife is indeed married to a US person ( Resident for Tax purposes ( with retrospective request via amended return ) and hence you should consider amending your 2019 return as Married Fling Joint -- include her world income for 2019 as US taxable income -- and include the "first year choice" and "alien to be treated as a resident for tax purposes " paperwork. If IRS refuses then you could ask them to cite regulation which disallows this and go on from there.
Namaste ji
pk
