There is mounting speculation that the duke and duchess - who divorced last year - and the princesses may all live together again under the same roof. Whether their first joint public appearance since August last year is a dry run for a future house-share is unclear.
But it is understood that moving back to Sunninghill Park, the former marital home, was one of several options being considered as the duchess prepares to move from her present rented home. A spokeswoman for the duchess last night said she was to quit the six-bedroomed Kingsbourne on the Wentworth Estate, near Windsor.
The duke and duchess, who have remained close friends since their divorce, are reported to believe a house-sharing arrangement would benefit their daughters, aged eight and six.
But their domestic arrangements seemed a million miles from their thoughts as the family took advantage of spring sunshine and ideal skiing conditions in the Alps.