Here are what senior ladies of the Royal family wore:

Her Majesty also wore a custom made/Bespoke dress. Saiid Kobeisy the Lebanese-born designed was the mastermind behing her bespoke couture floor-length kaftan gown, which features celestial shades of blue.The dress is designed into the abaya style, which is a long, flowing dress that drapes over the body in a loose manner. The beading features floral patterns distributed along the dress and sleeves and a constructive and soft way; it includes gold threads and sequins. The middle of the dress is made from plissé crepe georgette, a lightweight and flowing fabric that adds movement and texture to the dress. 

She accessorized with Mattar Jewelers unique pearl embellished clutch & re-wearing a pair of Vanleles “Kilimanjaro” white gold & titanium diamond earrings.

Her Royal Highness Princess Iman was wearing a light purple/pink satin embroidered abaya accessorized with her mother's Rafe Sara Faceted Shell Minaudiere

Her Royal Highness Princess Salma was seen wearing a red long sleeved kaftan with embroidered on the sleeves. With black Jennifer Chamandi Lore 65 Leather Pumps and FENDI FF Embossed Wallet on Chain Bag