Alright, here's how Fuzzboob works.
She waits a set amount of time. After that set amount of time, she will move UNLESS you have your camera up or you've stunned her on cam 6. If you have, she will just wait for you to stop before immediately moving.
That set time is 77 seconds, regardless of difficulty.
You can use this to your advantage by setting a 70 second timer and then closing the door at the end of that timer until she moves. After that, fuzzboob is defeated. She will not have time to attack you again. If it wasn't for that 77 second thing, 4/20 might have been impossible.