The 3 Princesses of Selmy Island

I have been thinking about this story non-stop! And I am so excited to share more information about it with you.
I am also looking for feedback to make sure I'm headed in a good direction before I get in too deep. Subscribe to my page to get a copy of my one page story synopsis and get a first look!
Anyway, here is the background on this story:
It all started when I was working my way through a world building course by Stephanie Bwabwa. She asked the simple question about how was the kingdom in your story founded? I realized I had no idea! And I started to think about it.
The Kingdom of Toraelium, which is where my current work in progress takes place, takes up the whole continent it is on. And it's way bigger than any of the other kingdoms son my world. So I had to think about how it got that way. Was it an empire? Did a small kingdom take over the whole continent?
Based on the government and nobility I had already created, I didn't really see it as being ruled by some emperor who taught to take it over. And since it was already made up of several smaller regions, I decided that it was a kingdom that had been peacefully joined ... But why? How about marriages?
I started looking back in the family tree I had created for the current royal family for a place that would work, and I discovered 3 sisters and thought "what if they were all from one kingdom and married princes from the other 3 kingdoms. And a story idea started to form.
I am currently reading a Court of Thorns and Roses by Sarah J. Maas, which is loosely based on Beauty and the Beast which gave me the idea that it would be fun to write a fairy-tale inspired story. I thought it would be cool to use a different fairy tale for each princess's love story.
So I started searching for the perfect fairytales.
I wanted stories where the princess was already a princess... And let me tell you, there are not that many of them. And even better if it had a connection to birds because each region of my kingdom is supposed to have a connection with a different bird.
So I thought of the Swan Princess.... But none of my regions were associated with a swan. So I kept searching and then by some miracle or miracles, I found an obscure Russian Fairytale, The Death of Koschchei the Deathless, which by some magical coincidence... Is about 4siblings- 3 princesses and a prince. And each of the princesses marries a prince who shows up to her as a different bird... What are the odds?
So this is a really strange fairytale, (you can read the original here in The Red Fairy Book, found on project Gutenberg) but two of the three birds were ones I had planned on using, and the family set up was right, so I did some tweaking to the kingdom to make all the birds line up (which acty led me to some cool new developments for my main book) and did a bunch of research on legends and lore surrounding the birds from my story. And came up with unique personalities for the princesses, which led me to the conflict and ideas for their story.
So anyway, I am really excited, but I'm looking for feedback on the premise and the one page synopsis I came up with. So if you like fairytales, and love stories, and cool world building, let me know and you can be among the first to read my ideas and synopsis and even give me feedback!
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