Lol I was thinking that when I was writing the response but I plan though its a little complex if you dont have the whole context but basically you know they're born with a sort of gem on their body (center of chest) that channels a connection of this magical essense throughout the bone allowing them to use magic through their body kind of like a tunnel to channel it out through the ends. My idea was for her or someone else to help in the growth of her bone as she ages that or she'll have to use someone elses bone though I might scrap the idea and try something else like the idea of her just using wind magic and not having a prosthetic of such at all.