Astrid

"Sergey, Zooey, now there's Astrid too. She may be from Freezenburg, but now she serves for the Russian people, building Tesla Tanks and training Tesla Troopers, as one of the three Ministers of Defence of the Russian Federation, as hired by Vladimir Putin."

--Su Ji-Hoon, The Coming Apocalypse

Princess Astrid is Princess Hildegard's older sister. She is seen in a flashback during the song "Know It All" in a Sofia the First episode The Princess Stays in the Picture. Her name has yet to be revealed on the show, but according to Craig Gerber, Astrid is her name.

In When the Cold Breeze Blows Away, she is the co-Minister of Defence of the Russian Federation, along with Zooey and Sergey Shoygu, as part of her duty to build Tesla tanks  and train flak troopers, which both of them are invented by Lisa Loud.