Moving it by email or using a thumb drive should not make a difference. But emailing is not safe or secure. Maybe she has another .tax2021 file on her computer.
you might have one that starts with a Tilde sign ~ like "~your name.tax2021". That file is if your computer crashes or your real file gets lost or deleted or corrupt so you can restore it.
Here's an idea. Do you still have 2021 installed? Try opening 2021 program and see if you can get your 2021 return to show up in it. Go to FILE - OPEN. See if it's the right one. Then save it again with a name and place you can find. Go to File - Save As.
