I just replied to your PM but I hadn't read your thread update. That is GREAT news that you've spotted her under a nearby deck!
I agree with Catty1 that a live trap is a good way to go at this point. You could call your local shelters and see if they have one they could lend you. The local vets might have one as well. You could see if they 'rent' them.
They are fairly simple to operate. You just set the trap so when your cat enters, the door will fall closed behind her. Just place the trap under that deck and put some food in the back of it and when she steps in to eat, the door will close.
If you do this, make sure to check the trap often to see if she has been caught so she doesn't stay in it for too long. Also, sometimes other animals get trapped instead of the cat that you are trying to catch.
I hope you are able to get her soon.
p.s. I was also thinking that it sounded like the 4 people trying to get her out from under the deck might have been a bit scary for her. She may not understand that you guys are trying to help her and 4 people might have been overwhelming for her. You might have better luck if it's just you and some food. Just a thought.