Henriette is mentioned by Alfonse and Sharena on multiple occasions prior to her introduction, mainly having shown support for Alfonse's desire to fight in the Order of Heroes and receiving numerous letters from Sharena during the Order's battle against Embla and later Múspell.
Returning home from their battle against Múspell, Henriette warmly welcomes the Order back home, much to their surprise. She informs Alfonse that Gustav wished to talk with him as soon as possible. Their reunion is cut short when mysterious, ghostly Emblian soldiers attack the Order. Henriette immediately recognizes them as soldiers of Hel.
Unlike her husband, Henriette is a more upbeat and cheerful person, serving as a doting mother towards Alfonse and Sharena, as well as whimsical at times, leaving the castle with no guards and letting slip that Gustav had missed his son during their first reunion since prior to Alfonse joining the order.
Also unlike Gustav, she lends a more supportive approach to Alfonse and Sharena's goal, believing that they can accomplish anything they want.
Henriette is the feminine variant of Henry. It is of Germanic origin meaning "home ruler", matching her title as Queen of Askr.