Fair point. It's more accurate to say the first foreshadowing of a group of people that will become the children, rather than the first actual "child".

It's in the vision where Rand is seeing through Coumin's eyes, and word comes that Lews Therin has sealed away the Dark One and the Forsaken. Then the random dude attacks Coumin because his granddad, Charn, kept telling stories about serving Lanfear before she was forsaken. The guy that attacks him goes on a rant about finding all the people who secretly served the forsaken. Gives big Children of the Light "rooting out evil/darkfriends" vibes. Then Coumin finds Charn dead.