K, I am intrigued, that is the first time you have given any personal information as far as I know - either you are far more advanced in years than your very agile mind suggests, or you started solving cryptics at the age of 2 or so! Lovely!
However, I totally agree with you about the effects of crossword familiarity. I take far longer than you, but even familiarity with a certain crossword (this one or the AZED) makes it a far speedier process. Having the right books etc. helps too. Zita should be reassured and not feel slow or limited.