if its anything like bearded dragons, it takes around 60, although mine took 55. you are up to 52 so far so not long now, just keep checking a few times a day
thorny devils are dragons to and a small dragon like the tawny dragons but last night after posting i saw 1 of the eggs sweating and a transparent bit on the shell, this morning there is a little head poking out when should the others start hatching?
They will usually hatch within a week of the first one (beardies anyway)
And what if I said I don't believe you - you must have pics of these little critters