Possibly a spoiler as based on comic books so will hide, don't read in the unlikely event it actually happens:
Probably rubbish
In the comics the 'Red Room' where the Black Widows train etc they take regulary 'mind scans' and have clones of all the Widow's, ready to upload their most recent memories into. Seems a little bit of a cop out for the MCU but if at the end of the solo film, or during it shows Natasha's memories being saved somewhat recently then I think it's what will happen.
Probably rubbish
