Exclamation [Q] Asus Nexus 7 2012 stuck in bootloop


My sister's Asus Nexus 7 2012 is stuck in a bootloop. She runned an app (I don't know which app), then it restarted and went stuck in a bootloop. She has very important files on her tablet and didn't make any back-up's. I tried to back-up the files with Recuva but the computer doesn't see the tablet. I tried Skipsoft Android Toolkit as well, but the program says that I have to turn on USB debugging and I can't because it is stuck in a bootloop.

I hope someone can help me and sorry for my bad English...

Bye bye,