I have found on Wikipedia these pictures of Archduchess Maria-Theresia, née Princess of Braganza/Portugal (1855-1944). She was the (third) wife of Archduke Charles-Louis (1833-1896), who was the third son of Archduchess Sophie - of whom we have seen she received the "Napoleon" necklace from ex-Empress Marie-Louise in 1847.
The lowest necklace, with its diamond drops, is very probably the "Napoleon" necklace:
As Archduchess Sophie died in 1872, Charles-Louis first two wives, who had died respectively in 1858 and 1871, could not wear the necklace. Only the third wife, Maria-Theresia, who married Charles-Louis in 1873, could wear the necklace inherited by her husband the year before.
On the following picture (dated around 1905), we can see Archduchess Maria-Annunciata (1876-1961), who was Charles-Louis and Maria-Theresia's eldest daughter. She was the abbess of the Hradschin abbey in Prague Castle before WW1, and died unmarried. I wonder if her lower necklace (the one with the drops) could be the Napoleon necklace (which would then have been lent by her mother):