Who is Adelaide Bevan from The Tin Princess and what is their importance?

Once a prostitute, Adelaide Bevan goes onto marry Prince Rudolf. When her husband is killed, she becomes the Queen of Razkavia and negotiates a treaty with the two Great Powers, becoming an assassination target herself in the process. Adeliade is injured defending the flag at Schloss Wendelstein and sent to Switzerland to recover. She and Jim later decide to marry.