I've had something similar happen after my hosting game had an unexpected crash.
In my case i'd already made a backup of the whole save right after the crash (just in case when mucking about

), allowing me to put back a .bak-version of the savefile of the player.
In my case the savefiles resided in %appdata%/7DaysToDie/Saves/WorldName/SaveName/Player/playeridinnumbers.ttp.bak
With any luck the last-saved state prior to the one you've tried to reload is still intact, this also gives you a chance to take a further look into wether she got a recreated profile alltogether (likely overwriting the old one) or something else may have happened (usually the console shows the playerID upon connection request; this should match with the ttp file which should have a readable profilename/charactername in the file if you open it with the likes of notepad)
Since I manually start and stop my server in-between sessions i've begun to copy my save before launching the server, just-in-case... much easier to give up progress gained over the last playthrough then to be forced to start over
Has any reason been found for the server crashing? In the long run that might be important. At least, I just run multiplayer from the game client when I don't have an actual dedicated machine for it and apart from the crash I mentioned I haven't had it crash again... yet.
Or to rephrase; if there's no specific reason to run dedicated on the same machine it might be worth investigating if that doesn't result in a way too large amount of memory consumption (even without seperate Dedi I often hit a 22-25GB commit-size while hosting 16k worlds, in my case)