Changing one's name is a funny thing. My older brother and my older sister didn't like their given names. (In all fairness, my brother's name was terribly antiquated and subjected him to huge amounts of painful teasing. He was named after our father and grandfather. Sigh.) So, in their teens and twenties they went by alternate names. I have a grand-niece who is named after my sister's alternate name in honor of her. But, after they lived with them for a while, they decided to revert back to their given names.
I, on the other hand, had a more common name that didn't deflect the teasing and insults, but I wasn't as bad with it as it
was reasonably common. I never really considered changing it. (But I didn't continue it with my kids.

)
I've been a writer and giving names to characters (and even writing under pseudonyms) is normal (for me).
So, when I was looking for my feminine name, I thought along the lines of many who have already commented. I thought I would go with a feminine form of my given name. I even looked up all the variants (and there are a LOT of them in the US and Europe). I picked one that seemed best. I used it for a while in my private journals, etc. But, somehow it never felt right.
The more I acknowledged her, the less the name I had picked seemed right. Then, when trying to figure out a handle for her to use in a forum, my intuition clearly told me her name is Jackie. And she was right. It was exactly right. It resonated. And she was ready to be introduced by that name (in public or in private). It's almost like she extended her hand to me and said, "Hi. My name's Jackie."
And so it has been ever since.
Hugs,
Jackie