You can do it with the windows cmd:
Go to a folder of your choice, click on the top bar in your explorer window (where your path is displayed), type in cmd and press enter.
This will open a cmd window in your current folder.
Now simply create a folder (for e.g. "examplegirl") and move all files starting with her name into it like this:
This also works for a word in the middle of it:
This lets you sort your collection easily if you have your files named after the person in it.
If you have linux the command "move" needs to be changed to "mv" instead.