Not much different after you die!
There appears to be a couple things going on here. A woma that smells food and expects to be fed is definitely a snake not to be taken lightly. I am wondering if your son had been handling a cat or dog or pet budgie or rat etc before he sat down and took over the snake. That would at least explain why it arced up initially. Your reactions to this situation and your son still being nearby would account for a sustained reaction. Following that the snake has had a scare and become stressed.
The advice of taking it slowly, slowly and leaving the snake for a while is very sound. It has had a rough introduction to its new digs and is reacting accordingly. A quick once-a-day check on it for the first week is the absolute max. Let it regain its feeling of security. If you attempt to handle any snake that really doesn’t want to be handled, all you will do is stress it out. At the same time you are training the snake to associate you with it being stressed. Under those circumstances, if you were the snake, how would you react to you reaching into your enclosure?
Follow the advice given. Provide it with maximum privacy until it is settled and then gradually start winding that back several days at a time. That will mean, at some stage, moving the viv into an area where there is a lot more traffic. Instruct the kids to ignore the cage and not look into it. The snake will soon enough stop reacting to passers bye when it realises that is all they are doing. This may well take a month but it is an investment in the future and the best thing for the snake, given what has happened.
To avoid getting an “I’m expecting food” response each time you got to the viv, you need to exercise a bit of discipline. Always feed your snake at the same time of day, preferably after dark as that is when they would naturally be out and about looking for tucker. Even feeding always from the one side of the viv helps. Accessing the cage for maintenance or removing the snake to handle it should always be done at a very different time to feeding. Make absolutely certain you have not handled potential food items or pets prior to removing the snake. If you have thorough wash with a strongly scented soap can help. Once the snake realises it is not about to be fed it should settle right down.
Don’t try and remove the snake from the viv if it is really putting on a full defensive display. However, if you think it might just be expecting to be fed and is reacting accordingly, then do so. I do realise it is not so easy to tell the difference but with practice you’ll get a feel for it. If the snake comes out and refuses to settle, it was in full defensive mode. Usually they will start to exit on their own. You can use a small snake hook just hold the head away from the body while you reach in and grab the body. The hook should not be used to take any weight of the snake, just to stop it from attempting to bite. After a while you should find that you don’t need the hook. If you are feeling uncertain, you can always were a pair of leather or heavy rubber gloves. That way if the snake did happen to latch on you won’t instinctively drag your hand out at a thousand miles an hour, poor snake trailing behind until your hand stops and then catapulted through thin air to land God knows where.
Good luck and be patient.
Blue