Dead to me / Lesley Pearse.

When Ruby and Verity met as girls they came from different worlds. Verity was privately educated, living in a beautiful Hampstead home, while Ruby was being raised in extreme poverty. Nevertheless they became firm friends. However, fortunes are not set in stone and soon the girls find their situations reversed. As Ruby goes up in the world, Verity encounters more and more tragedy, but still the girls remain a large part of each other's lives. That is until one day in 1938 when Ruby says the terrible words 'You're dead to me' and it looks like their friendship might be over for good . . .