I believe this to be the RBT family. I heard the soft cycling of one of the fledglings begging, and found the family arranged closely along the branch. Mum and dad groomed each other, then both groomed the girl. Dad groomed the boy briefly, then they had a bit of argy bargy, wings spread and growling. Both fledglings began begging in earnest, and dad fed daughter, mum fed son, before they all flew off.