[aegontargeryen]

If  Gamora can be brought back from the past, why not Black Widow? Gamora and Black Widow  died for the same cause.

[pumpkinbreeze]

Gamora wasn't brought by but rather another gamora was brought in from the past. which will have a very much different life and experiences.

This doesn't discount doing the same for black widow but you would be taking that black widow out from her timeline and abandoning her sister