Skull Theory?

Nicola • Mommy to the most loved, beautiful angel in heaven.. Giovanni Antonio Brown born January 21st, 2017 👼🏽❤️ My beautiful rainbow baby Ezra was born December 20th, 2017 🌈👶🏽💙 now expecting baby #3 12/2021 🥰
I'm not even 12 weeks yet but I swear this baby is already sucking it's thumb 😂 but anyways, maybe someone can help me with the skull theory? TIA. ☺️