I’m afraid I don’t know anything more about Alice and Rosie’s tiaras. I would guess that they belong to their families.  Rosie’s tiara is a style called a modified fringe tiara which is a pretty common design in the late Victorian & Edwardian eras but the Swedish Modern Fringe Tiara is the only one that currently belongs to a royal.  Queen Mary had two of them (her Wedding Tiara and the County of Surrey Tiara) but she apparently wasn’t fond of the design and dismantled both of them to create other tiaras.  Most modified fringes have these thin fleur de lys-ish elements that almost don’t look like fleurs de lys anymore and the fringes have only a few diamonds spaced out instead of a solid pointy spike.  Like regular fringes they are usually convertible to necklaces.  I’ll work on getting a tiara motifs post on the modified fringes so you know what I mean because I’m bad at describing them.

Lady Tamara Grosvenor at her wedding to Edward van Cutsem in 2004 wearing the Westminster Myrtle Tiara

Rose Astor at her wedding to Hugh van Cutsem in 2005 wearing the Heathcote Tiara borrowed from her cousin, Jane Heathcote-Drummond-Willoughby, 28th Baroness Willoughby de Eresby

Alice Hadden-Paton at her wedding to Nicholas van Cutsem in 2009

Rosanna ‘Rosie’ Ruck-Keene at her wedding to William van Cutsem in 2013

Here’s a comparison with the Swedish Modern Fringe Tiara.  Rosie’s doesn’t wrap as far around the side of the head, has a more solid diamond base, and has spikes with three diamonds interspaced with the fleur-de-lys like elements.

A few years ago there was some discussion that the Swedish Modern Fringe Tiara might be the same as the one owned by Leonora Bennett, Countess of Tankerville (x)(x)(x) but the quality of the pictures really aren’t good enough to tell for sure and like I said is was a common design.

Cordelia:

Cordelia: hey he’s kinda cute

Heathcote: cordelia no