I've always thought the tiara was just resting on top of the fur trim around the base of the coronet.
--Previous Message-- : : This pic of the Duchess of Connaught and : daughters Margaret and Patricia completes : the series for the jewels and coronets they : wore to a number of coronations. : : I always find the tiara worn by the Duchess : to be rather awkward. : The top fringe tier does not seem to fit the : lower tier very well. : : Pic from the Royal Collection : : :