Is what I uttered considered a vow that necessitates expiation, given that I did not pronounce the name of Allah, did not specify the newborn, and did not consult my husband?

A vow (nadhr) is a commitment made by a legally competent Muslim to perform an act of devotion to God that is not originally obligatory. It requires a specific formulation that indicates commitment. The statement: "If I am blessed with a daughter, I will name her such-and-such" is not considered a valid formulation for a vow. Even if we assume there was a formulation indicating commitment, vowing to name a newborn a specific name is not an act of devotion. Scholars have differed on its validity. The Hanbalis held that it is valid, and the person who made the vow has the choice between fulfilling it or offering an expiation for breaking an oath (kaffarat yameen). Therefore, there is nothing binding upon you regarding what you said.