have 21`yr old grey female that has recently started cooing and moaning I think she is trying to nest still eating and bathing just constnatly making strange noises
Could be a hormone thing, but she's 21 and probably would have done this before ... I bet it's a new behavior that she has learned, like a mimic, that got he attention in the past and she's trying it again to get more attention.
As Missi said, more details would be handy. It could be so many things that trying to figure out from this would be pretty speculative.... but hey I can speculate with the best of them:
If you think she is trying to nest you need to make sure she gets plenty of calcium. If her 'noises' suggest discomfort or pain and you think she's trying to nest then definitely see a vet - egg binding is a possibility (Though it's one among too many possibilities at the moment).