Assuming it won't even talk to a PC or Mac, I would assume that a remote backup is the only hope.

Didn't the recent kerfuffle about unlocking a dead shooter's iPhone (5c) tell us that later iPhone models were hardware encrypted and even swapping chips wouldn't let you get inside? (I can't find a link that says that, but that was my recollection.)

Here's hoping she was able to get what she needed via some sort of backup.

Cheers,
Scott.