Or at least that's what it looks like to me. This is the one that was flitting around the other day. Her feathers dont look as smooth as you usually see & she looks a little thin, so I think its a new mum trying to keep the babies well fed.
Had to laugh at your words but they are spot on……she does indeed look very busy & stressed! Keeping these babies fed takes all our time! No time for any grooming today!