She hid her face in Lady Mary's neck, half laughing and half crying.

"I was so afraid you--you were taking him seriously; and--and he was so selfish, wanting to keep you all to himself." "Oh, Sarah, hush!" Lady Mary cried.
She divined it all in a flash, in the twinkling of an eye.

It was to Sarah that she owed the pain and mortification, not to her boy.
Sarah had said Peter was not responsible.
Was he only a puppet in the hands of the girl he loved?
Could John ever have been thus blindly led and influenced?
Her wounded heart said quickly that John was of a different, nobler, stronger nature.

But the mother's instinct leapt to defend her son, and cried also that John was a man, and Peter but a boy in love, ready to sacrifice the whole world to her he worshipped.

His father would never have done that.
Lady Mary was even capable of an unreasoning pride in Peter's power of loving; though it was not her--alas! it never had been her--for whom her boy was willing to make the smallest sacrifice.
But he had honestly meant to devote himself to his mother, according to his lights, had Sarah's influence not come in the way.