Help a newbie out - how long from first hatch to last?

[Achelois]

Update - our chick is looking good! Weak, but it's got spirit! Pretty much dried out and fluffy-ish now (well, a bit sticky from dribbled electrolyte). But eyes open and trying to walk/thrash around. It was an amazing turnaround it made. I'm hoping in a few days if it pulls through and it's as strong as the others I can give it back to mum?

https://www.backyardchickens.com/t/833086/help-half-dead-chick-with-photo#post_12202612

 

[sumi]

Wonderful! Keep it until it can walk and get around o.k. and then go slip it under the hen.

 

[Achelois]

Will do. The electric blanket stopped working last night, **** it. Didn't find it until this morn and I'm worried it got cold as it looks a lot sleepier. I had the heater on in that room but the box wasn't as warm as it should have been. Have filled another hot water bottle.

 

[Achelois]

Oh dear! It stars 'd*mn'? Looks like I said a much worse word. I promise I didn't!