Wife of Ferdinand I.  Although their marriage had been made for political reasons, it was very happy.  Ferdinand called Anna "after God, my greatest and dearest treasure". 
He was so devoted to his wife that it was said that he never took a mistress. (This was not the usual behaviour of 16th Century royalty, as witness his contemporaries, Henry VIII of England and Francois of France.)
 
Ferdinand and Anna had fifteen children, but I only know the names of twelve:  Their daughters were Elizabeth (1525-45) who married the king of Poland; Anna (1528-90) who married the Duke of Bavaria; Maria (1531-81) who married the Duke of Cleves; Magdalena (1532-90) [I have no information on her]; Catherine (1533-72)  who married the king of Poland; Eleonora (1534-94) who married the Duke of Mantua; Margaretha (1536-66) (no information) ; Barbara (1539-72) who married the Duke of Ferrarra and of Modena; Johanna (1547-78) who married the Grand Duke of Tuscany.
 
(Three daughters became nuns). 
Their sons were the future Emperor Maximilian II (1527-76); Ferdinand of Tyrol (1529-95) and Charles/Karl of Styria (1540-90).

Source: Sandra White