Fetching details from the dictionary...
daughter of a person of high rank (esp. eldest daughter)
物語の姫君は勇敢だった。
The princess in the story was brave.
姫君は城から抜け出して旅に出た。
The princess slipped out of the castle and set off on a journey.
昔話に登場する姫君の多くは美しく心優しい。
Many of the princesses in old tales are beautiful and kind-hearted.