Dusty Answer by Rosamond Lehmann

Mamma was fast asleep at home, her spirit lapped in unconsciousness. Her dreams would not divine that her daughter had stolen out to meet a lover.
And next door also they slept unawares, while one of them broke from the circle and came alone to clasp a stranger . . .'

Judith Earle, over-earnest and inexperienced, has always been a little in love with each of the four cousins who come to stay next door and, on her return from Cambridge, becomes madly in love with one of them - Roddy, the 'sensation-hunter'. DUSTY ANSWER traces with delicate nostalgia childhood friendships and the pangs of thwarted young love.