Only Hester and her children knew that Hester could not love anyone. To those outside the family, she appeared to be a good mother, one who adored her children. But Hester and her children knew of Hester's cold affection for them as they "read it in each other's eyes." This was a family secret, unknown to those outside the family.
Uncle Oscar, Bassett, and Paul keep the secret that they are betting on horse races. Paul does not want his mother to know where the winning money has come from, so Uncle Oscar arranges to have the family lawyer say that it came from a family relative. Despite this gift, the house's voices (the house's secret) became more frenetic:
There must be more money! Oh-h-h; there must be more money Oh, now, now-w! Now-w-w--there must be more money!
When Paul's mother, Hester, receives the letter about the inheritance from the family lawyer, she hides the letter. Paul and Oscar agree to let her have the entire $5,000 to pay her debts. But it seems Hester wastes some (or all) of this money on luxuries: new furnishings, flowers, and iridescent cushions.
Paul believes that there is some connection between the house's voice and the rocking-horse's magic. This is the biggest secret. Not even Oscar and Bassett knew of this:
Paul's secret of secrets was his wooden horse, that which had no name. Since he was emancipated from a nurse and a nursery-governess, he had had his rocking-horse removed to his own bedroom at the top of the house.