This is my first foray into chickens. 3 weeks ago a friend of mine sold me 5 of his young laying hens. One a splash EE I'm not sure has laid any eggs for me but my son swears she laid one. Then on sunday o saw her have a green watery poop, yesterday I saw her vomit up water to which all the other chickens ate, then this am again i saw a watery green poop. Have not changed feed or given any table scraps, has grit. She seems fine temperament wise. Comb light pink. Should I be worried? What do you think it is?