oh Aly, i really feel for you...
although 2 babies are a lot easier to care for than 5

to make a cheaper incubator, but one that involves a lot more monitoring, go to an aquarium/terrarium store (a pet shop that sells fish and reptile stuff- any pet shop selling this will do) and buy a 'heat mat/pad' for a lizard or snake, and also a thermometer...
then set the heat mat up in a box, with towels over the top, then monitor the heat, when you have a good stable temperature, put the eggs in a layer of towel with the best temp, making sure the eggs are covered on all sides, then you just have to watch and turn the eggs...
this will work if they decide to abandon the babies when they are close to hatching....
i am sure it will all happen when it is meant to

they love each other, and are both healthy and have a lot of time, and have a wonderful caring mother, so just don't worry!
maybe they just decided they had 'bitten off more than they could chew' with 5 babies....
and indeed a couple more months experience will do wonders, maybe this was just a 'trial run'

good luck Aly, Baby and Ziggy and the 2 remaining children