Person (18 years or older), born in the Bahamas, but whose parents were not citizens of the Bahamas. Person (18 years or older), born in wedlock outside the Bahamas to a Bahamian mother. Child adopted by Bahamian citizens.
I don't understand the point of your post. The baby is not 18 years or older, so she does not have Bahamian citizenship, though she will have the right to register for it and become a Bahamian citizen at any time between her 18th and 21st brithdays. Meanwhile she is a citizen of the US only (unless some citizen of the Bahamas or of some third country turns up and it able to prove biological paternity). My understanding is that the Bahamian government's current position is that the man on the birth certificate -- US citizen Howard K. Stern -- is the legal father.