Have you tried the "Wee Stinker" in the Herald? That's our local paper, and it's an extra difficult crossword from usual. My Auntie was legendary with it, and now my mother does the Herald crosswords pretty quick (a dram helps she says). I will forward the Rosmarie question see if she can give a full answer, and if you need any more details I'm sure she could answer.

Apart from that, I'm hopeless at crosswords - my mind is not wired that way heheh. So it doesn't run in families all the time apparently.

Dave L