Hey everyone! Thanks for all the suggestions they helped a ton. Sorry I didn't reply earlier I had everything happen at once and it's been hectic. My daughter's cat had something called Chyle leaking into his chest cavity and it was compressing his lungs and heart

we tried everything the vet recommended but he didn't get better and I ended up having to get him put to sleep.
Anyway, I started introducing Little Bird to the others by putting his cage close to theirs everyday. They started talking to each other more and more and seemed to enjoy having little bird around.
Two days ago I put them in the big aviary and they all three instantly got on the same perch! I thought it was funny because I give them this huge aviary and they all snuggled together on a little 5 inch perch.
I've been watching them closely and they are doing great, they've been moving around the cage playing and singing and they found the food and water with no problems. It's been awesome to watch. I haven't noticed anyone being left out or any altercations as of yet either. Pogo (the one I think is a female) kinda pushes the others around but not in a aggressive way, she just seems to be the dominant one of the three.
Thank you all again I really appreciate your help. I'll post a picture of them as soon as I can figure out how to do so.