I just finished the 1971 version of "The Hooded Hawk Mystery", and in it Frank and Joe are gifted a peregrine falcon whom they name Miss Peregrine. At first the falcon is to help with the case, but then on the last page the original owner says that he's giving the falcon to the boys as a gift for solving the case.
I'm trying to remember, does Miss Peregrine show up in later books, or does she just disappear?
But I guess there is precedent for the boys owning a bird in the UB continuity with Playback.
Nice connection there! I do remember Miss Peregrine from that book, but I don't recall if she's ever mentioned again. I would guess not though.