Who was this Holy Roman Empress and Queen of Spain, Germany, Italy, Naples and Sicily and Duchess of Burgundy whose influential friends include Leonor de Castro Mello y Meneses?
Leonor de Castro Mello y Meneses:  She was a noble Portuguese and the Lady and close friend of the Empress Isabella of Portugal. Isabella of Portugal: Isabella of Portugal (Portuguese, Spanish: "Isabel"; French, Dutch, German: "Isabelle"; English: "Elizabeth"; 24 October 1503 – 1 May 1539) was a Holy Roman Empress and Queen of Spain, Germany, Italy, Naples and Sicily and Duchess of Burgundy by marriage to Holy Roman Emperor Charles V, and regent of Spain during the absence of her spouse during 1529-1532, 1535-1536 and 1538-1539.
Isabella of Portugal