Question

Explain as for my grandmother being young and pretty,the thought was almost revolting

Answer 1

this means that narrator cant believe that his grandmother was once pretty and beautiful...i think this is from chapter the potrait of a lady

Answer 2

Since his childhood, Khushwant Singh saw his grandmother as an old woman. She appeared so old to him that he could not evoke his common sense to understand that old people have a birth and childhood. There was nothing in his memory that revealed the grandmother's aged appearance to her youth and beauty.