Elisabeth's family got the diamond tiara from GD Helen. Archduchess Sophie (cousin of the Kents) wore it at her own wedding.
Some of these blogs are just wrong --their "research" consists of reading other people's blogs, not the original sources. Ursula's wonderful site royal-magazin.de uses primary sources and original news reports.
That's the same info I had, especially given the reports on Miechen's inheritance, they divided their jewels according the either gem/pearl. If I remember this right, GD Helen got all the pearls, her brothers got the rest of the stones.