Some other tiaras:
Dona: A diamond and aquamarine tiara with matching necklace and earrings:
An emerald tiara (which looks very tiny perched on Dona's large hairdo!).
I think it may be this emerald & diamond tiara:
This tiara dates from the early 1800s--it may be of Russian origin and then brought into the Prussian royal house through inheritance. It is designed as a graduated bandeau of triple laurel leaves. There are 13 larger round diamonds which compose the 'buds', with 5 pairs of pear-shaped cabochon emeralds topped by diamonds. They are mounted in silver and gold. This tiara was inherited by Victoria Louise. It had been received by Dona in 1906 as another tiara from Wilhelm to commemorate their silver annivesary. It went from Victoria Louise to her daughter-in-law Sophie of Hanover. It was sold in 1974.
Cecile (in a lovely portrait of her) in a ruby tiara: