Perhaps some silk head ornament... anyway, not a "real" tiara to my eyes...
--Previous Message-- : do we know when the photo was taken? : : there are 4 years of age between Sofia and : Irene... and most royals do not wear a tiara : before the 'coming of age'... : : so if Sofia is 20 or 21 in this photo then : Irene is 16 or 17 years old, and thus not : old enough to wear a tiara... : : then it could be some kind of head ornament : (in fabric? perhaps) in the shape of a : kokoshnik... :