That's Not a bad Idea, but I will have to admit that in 2013, 2014, 2015 I set over 150 broody hens and never needed or pre-set-up a brooder. Guess I was Lucky!
When healthy chicks hatch, in a little while they are on their feet moving around some-----yours sounds as though it has problems---which might be why the mother abandoned it. It might not make it, then it might----I am not there to see what its doing but I would give it some time to see if it...
Use a lamp, take the shade off and lay the lamp on its side securely propped up where the heat on the floor below the bulb is around 100 degree's(not higher and not much lower----you need to check it with a thermometer. IF and When the chick is up on its feet and moving around good---then you...