We think she was sick, I'm not an expert but she seemed to have developed a cough or something (it's what it sounded like, not her normal calls.)

From what I was able to determine based on the area we found her in, she seemed to have wandered off while the male was sleeping or something, and just layed down and died.

We found what was left of her body, in a fairly dense overgrowth area, with no clear path to water or open field.

Alot of feathers, but no blood at all on any of them that we could find, much like she had wandered off, died and froze. She was eaten (mostly) by the Coyotes we have here, which is why we keep the water open in the winter.

It's the only explaination we can come up with, as now in hindsight after watching the males behaviour of "searching" he clearly didn't know where she was either.

No clue on the age, they seemed to me full grown and probably 7 to 9 years old as a guess.

Were going to keep feeding him and taking care of him, a new mate isn't an option I don't think for the reasons you mentioned.

One day we will probably adopt a new pair if we can, until then were happy to just keep taking care of him as much as we can.

Thank you very much for your assistance, it is very much appreciated.