This one might even be better.
Especially since you said you have a Buff Orpington. :)
https://www.backyardchickens.com/threads/easter-eggers-and-buff-orpingtons-growing-up-weekly-pics.763595/#post-10861486
This post really helped me when I was trying to get an idea how old my chicks were. Kept track once I used these pics, and judged by when they all started laying how close I was. Was spot on with 2 of them and the third I was a week off, if it wasn’t that she started laying a week later than...