This is about the age of puberty for older girls and younger girls. Cat fir is what an older girl would have down there. The reference to a kitten would be a younger girl. Not a lot of hair down there.
The saying "Cat fir, kittens ain't got it" Or Cat fir, kittens don't have it
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)