Muslim cleric Siraj Wahhaj has reported that the remains of a young child found on the New Mexico compound are those of his missing grandson.

https://www.google.com/amp/amp.fox5atlanta.com/news/grandfather-of-missing-georgia-boy-says-the-child-s-remains-were-found-at-a-desert-compound-in-nm

I can not find any reference as to how the grandfather knows the remains are those of his grandson but he appears to be speaking out about it.