As a person who has written fantasy non-professionally (though I would like to change that), I could maybe explain how I came up with Halei, if that would be helpful.
Halei-Helai kind of came out of frustration for me, because I have had difficulties in the past being visually descriptive and with fleshing out a character's personality. So, I endeavored to create a character disconnected from any sort of story, and I decided to give that character as much detail as I possibly could in just about every aspect I could think of. The questions I was trying to solve weren't like "what is her personality" or "what does she look like". I made it really, really granular and instead was asking things like "what manner of speaking and writing does she possess", "does she wear jewelry? How does it look if she does?", and "how do the things she dislikes relate to the things she likes?"
When I got down to the real tiny elements of the character I was writing, something weird happened and writing Halei became very easy, almost like she was writing herself. It is one of the craziest bouts of inspiration I have ever had. It was a relatively effortless and smooth process whereas before writing characters was always a huge burden for me. Halei didn't get elf ears because I thought it would be cool, but because it just made sense. Halei's bracer inscription wasn't for fluff but served a very important purpose that just integrated very nicely with her background through no intention of my own. I have never experienced anything like that before and I knew I stumbled upon something very special and personal to me.
I guess the long and short of it is when it feels like your character or fursona is just kind of writing itself, that is the one you want to choose and hold on tight to.