Exile of the Duchess from court circles could mean the Queen seeing less of the children, who are fifth and sixth in line to the throne. Previous royal divorces have ended with the children staying with their mothers, who themselves remained within the Royal Family. But while Princess Margaret and the Princess Royal are the Queen's blood relations, the former Sarah Ferguson is not.
Beatrice, seven, and Eugenie, six, are expected to continue living with their mother, seeing their father only when he is on leave from naval duties. The Duke, a senior pilot, is believed to have taken a shore job in an attempt to save his marriage. But responsibility for two small girls at home could be an unwelcome complication.
Since March 1992, when the Palace announced that the Yorks were discussing a separation, the daily lives of the girls have been turned upside down. Soon afterwards they moved with their mother from Sunninghill Park, Berkshire, and lost their normal family relationship with their father. In August 1993, they lost their nannies, Alison Wardley and Sally Fish, who had been with the Duchess since Princess Beatrice was born.
Marriages of couples with small children break up every day, but rarely with a worldwide blaze of publicity compounding their isolation and sense of abandonment. The strain on Beatrice and Eugenie has been clear. There have been times when they have thrown tantrums - and even tableware at other diners in a hotel restaurant.
Zelda West-Meads, of the counselling service Relate - whose patron is the Princess of Wales - said: "Kids whose parents are being divorced often regress to a younger age, thumb-sucking and bed-wetting. These children suffer a lot of pain and damage. Their lives are never the same again."