Adding 1 4-day old chick to 2 13-day chicks

[My Three Chicks]

Has any one done this? Can I put them immediately together? Any suggestions would be appreciate. I’ve had the older chicks for a week now and looking to pick up the younger one Sat. (I was given the wrong breed so I’m exchanging that chick for the right breed but they only have younger ones).

 

[rosemarythyme]

Would be best to have a divider in the brooder if possible, just to let the new addition get acclimated for a day or two first. If that's not doable, then at least keep a close eye on them all the first day to ensure the new chick is able to eat and drink without issue from the others.

 

[My Three Chicks]

Would be best to have a divider in the brooder if possible, just to let the new addition get acclimated for a day or two first. If that's not doable, then at least keep a close eye on them all the first day to ensure the new chick is able to eat and drink without issue from the others.

The brooder isn't very big...especially if I have 2 waterers and 2 feeders but I'll see what I can do to separate the baby for at least a little bit to make sure she's good and strong first.

 

[rosemarythyme]

The brooder isn't very big...especially if I have 2 waterers and 2 feeders but I'll see what I can do to separate the baby for at least a little bit to make sure she's good and strong first.

For short term use you can just have a small, very shallow dish of water, and same for food. I didn't have a feeder at all for my first batch of chicks, I just put the food on plates.

 

[My Three Chicks]

Well so much for keeping them separate!
I found a bigger box and separated it with a partition where the 2 Bigs (Bielefelder and Ameraucana) and 1 Little (Easter Egger) could see each other. (Used little bowls like @rosemarythyme suggested!). I made sure the Little was doing well. She is! Very active, confident, snuggly too! But she kept crying and looking at the other side of the partition. So I removed the partition and voila! They are 1 flock!

She and the Ameraucana pecked each others beaks a bit (more out of curiosity). But they are all eating and drinking together and making a big mess of the shallow food bowl and using the shallow water bowl as a wading pool!
You can see their size difference in pics!
She stopped crying now that she's got friends/sisters again!