Nice article! However, I believe that you meant that J0815+4729 actually contains 15% more carbon than our sun!

I happen to have written a similar article on Sunday explaining how we can estimate J0815+4729's age by knowing its composition.
https://steemit.com/physics/@thequantumknight/estimating-the-age-of-stars-j0815-4729-one-of-the-oldest-known-stars-in-the-milky-way