What CC Account Was I Logged Into? (+ File Recovery)

Hi all,

I created a project in Adobe Sketch last year on my dad's iPad. We got logged out of the account, and when we logged back in, the project (and all other files) were gone... I think we may have been signed into a different account, and he doesn't remember which one it would be. I am now unable to recover the document.

Is there a way check the history of what CC accounts have been logged into on a device (iPad in this case)? Or does anyone have any other ideas for recovering my project?

Thank you very much!