It's pushing the upper edge... that would put it at 100.4°f. The max recommended if I recall is 100.5 though "by the book" you can go as high as 102. (38.8c)
37.2°c to 37.78°c is the same as 99-100°f so yeah, 37.5°c would be right in the middle @ 99.5°f If you want, place the eggs in an egg carton with the bottoms cut out of each holder. Then all you have to do is rock the carton 45° either side of vertical 3-4 times a day. You won't have to touch...
Really? You're breaking your sisters toys over this? What did she do to deserve that? VERY childish! You don't sound responsible enough to me to even have animals in your care. If it doesn't do what you tell it to, are you going to wring its neck?
That is not even something to joke about... :( If you are serious, please seek out help NOW! That would indeed be a pretty stupid reason to take your own life. :( You can buy an incubator for less than $100. You could probably find one cheaper than that on Craigs List. Hell, you could build...
It's not that she "can't" or that she "can"... ANY chicken "can" brood and hatch chicks. The thing is, with most production breeds today, broodiness has been bred out of them in favor of continuous egg laying. Every now and then, the "broody gene" pops back to the forefront and you'll get a...