I’ve seen individual “shorty” chicks a few times in the past but I believe this was the one and only time I’ve photographed two recently fledged siblings together.
Many species just don’t look good in very low light but I think Short-eared Owls can be an exception, probably because their contrasting markings make them stand out so well.
Light like this very rarely occurs in bird photography that doesn’t involve setups or some other kind of manipulation, especially when the subject is a wild Prairie Falcon.