John has a son aged four, so he has been married at least five years. I would guess that he is thirty or more. So he would have been 10-12 years old when Elinor was born and probably somewhere at school and home only for the holidays. A boy of that age wouldn't much care for small children or mothering by a stepmother. If he had been affectionate of his own mother, he could even resent the new wife and children.