I'd try a different spot nearby. Maybe he's not liking the blind? I know it's hard with kids to get them not to move, but I don't think a blind is necessary if you have good camo including face and hands and don't move. You said you're not hearing him until 2:30, what's he doing the rest of the morning? No gobbles just before light? Have you tried roosting him in the evening? I'm guessing he has some hens he's with in the morning and after he's finished with them he goes looking. If he's coming out in the same general area and you could get someone else to help out, you could set up with your boy close to where he comes out and have someone else call from where you have been sitting. Sometimes decoys are a bad thing especially with an older bird that has been shot at or spooked in connection with them before. You might want to locate an easier bird, the big ones are usually big because they are extra wary, I won't say smart because I think they are dumb, but have incredible senses and are wary. If there's a Tom hanging around, usually means there's hens and that usually means more Toms. The one you're seeing may be the dominant bird and has been kicking so much butt that the other Jakes and smaller Toms aren't vocal, and are staying near the hens after the big bird is done. It might be tough with only 4 days left, you definately want the bird close, I like them within 20yds, especially with a kid. Don't get locked onto a particular bird with a kid, most kids would be more than happy with a Jake with only 4 days left.
Not sure of your whole setup, posted land or whatever, but here's what I'd do, try and locate some birds on roost around sunset, usually an owl call will make them gobble, if you can pin point them great, don't try and get to close. Get back there well before first light and try the owl call again, they may or maynot gobble, if they do great, if not now you have to make a decision wether to stick with it because you know thet were there last night or try to locate some other bird. If he's there try and move in, if it's good and dark you can get with 100 or so yards, but if it's not full dark keep back further, NO FLASHLIGHTS, be vey quiet, breaking branches is not so big a deal, but no talking, gun loading noises etc. Pick a spot you can see good towards the bird with no fences or natural obstuctions between you and him, no blind, back to a big tree if possible, good camo, gun pointed in the right direction, room to shift right or left if necessary, usually works best for a small kid to sit between your legs so you can help them more and whisper etc. Once you're set up wait a few minutes and give a few yelps, not sure what kind of call you use, I just bought a new Knight and Hale Tom Coffin and really like it, but the push button type calls are my favorite, easy to use and make the right sound, I've got all the other ones and have used them, I just find the push button ones to work the best and easiest. Hopefully he's gonna gobble right back at you, make him wait a bit then give him another yelp, I usually just wait after that, he knows where you are, but sometimes if I have someone new with me I'll try and keep him talking if he will, it adds to the excitement for the other person. ( this can be a bad thing if other hunters are around ) usually less is more when calling. Now if you haven't spooked him, he will usually either fly down headed for you or go off with some other hens if this happens and the other hens are talking now you have to call the hens to you and hope he follows, I'll usually make quite a racket, duplicating what ever the other hens say, cutting and yelping, whatever it takes. If he heads off with other hens ( if it's that late in your season hens should be about done with the Toms, this usually makes for easier hunting ) and they won't come, you can either wait until he gives up on them and comes back looking for you( this might take a few hours ), because he remembers where you were as long as you have'nt spooked him or you can try and get ahead of where they are headed and wait, which is pretty tough especially with a kid. Or look for another bird, I usually have about 3 places in mind when I head out in case someone is in my spot or whatever. But if you know you have birds around it's usually best to wait it out, maybe throw out a couple yelps every 15 minutes or so, don't move and stay very quiet as far as talking etc, again tough with kids. If he does head right towards you when he flys down, don't call much, he knows where you are, his gobbles are going to sound farther away after he flies down, sometimes you can hear his wings, hopefully he's going to head right to you, if you hear him headed your way, get situated, gun up rested on a knee pointing towards where you think he's coming and Don't Move. If you can see him stop calling and Don't Move. He might stop and strut and gobble a little, but without a decoy he has to keep looking. I like to have some sort of natural obstuction between me and him like a big rock or a small hill or big tree that he thinks his hen might be behind because he can't see it and knows it has to be here, so when he comes around looking for her he's in range, BAM it's all over.
Sorry for the long post, I know there's no way to cover every possible situation, maybe you can gleen a little useful info from my rambling, I still have a couple weeks before my season opens. When I scout for birds, I'd rather find 1 Tom alone in the woods than 10 Toms together in a field. Field birds have been seen and called at by every body and their brother for weeks before and during the season. BTW I'm a registerd hunting guide here in Maine and have taken many turkeys myself and guided a bunch of people on their first hunts even a deaf guy. Good luck and let us know what happens.