She deleted it. Then reinstalled her OS for good measure.
If you possess this file, you can verify its exact nature using a tool like or a standard emulator like Kega Fusion .
You may see various filenames depending on how the ROM was dumped: sonic3.bin Sonic_and_Knuckles_w_Sonic_3.bin S3K_combined.bin
If you're having trouble getting the file to run, let me know: Which or mod are you using?