Which tiara do you mean? There is no tiara which was worn by all three daughters-in-law.
There are two floral motiv tiaras in the Luxembourg jewel collection. The larger one, also called vine leafs tiara, was Claire’s wedding tiara, Stephanie’s pre-wedding tiara and never worn by Tessy. If my count is correct, MT wore this tiara three times.
The smaller floral tiara was worn several times by Alexandra, but never by any of the daughters-in-law. MT has worn this tiara since she came into the family and has loaned it also as wedding tiara to AD Marie Christine and Adélaïde Drapé-Frisch.