I'm feeling a bit thick.
I've completed the grid and highlighted 2 clue answers for a total of 11 cells but can't, for the life of me, find the 3rd relative.
I have perused every list and website on the subject, scanned the grid 10 times. The penny has yet to drop. Something's wrong with me.
I'm starting to suspect that some of my clued entries are wrong, and that some of the letters that would help me are misplaced.
Took me a couple of hours to fill the grid on Sunday morning, yet here I am still puzzled by the endgame on Thursday...