You're right, she would be woderful with ruby earrings, and they could match her ruby floral necklace.
Having a better look at them, I've just found components to make earrings similar to the new ones worn by the Duchess of Cambridge (I think I've never spoken about this here, but I like to make jewellery for me and my friends): http://www.hobbyperline.com/perline/perline-strass/marcasite-strass
--Previous Message-- : It is strange because the Duchess of Cambridge : has never worn ruby earrings. She has worn : : diamonds, emeralds, sapphires, pearls, : semi-precious stones, gold, silver....but no : ruby ! Please wear ruby ! : : Franck : : --Previous Message-- : The earrings are reportedly by Soru : Jewellery. : They're made of baroque pearls and Swarovski : crystals set in sterling silver clad in : yellow gold vermeil. : : More here: : New Earrings for Kate at the Natural : History Museum : Kate Repeats New Earrings at Wimbledon : : :