[Extremely Extreme Extremist]

her infant son, Barack Obama Jr.

Zero was 5 or 6 years old in 1967. That's not an "infant."

[NotThere]

In legal usage, yes it is: in·fant    /ˈɪnfənt/ Show Spelled[in-fuhnt] –noun 1. a child during the earliest period of its life, esp. before he or she can walk; baby. 2. Law . a person who is not of full age, esp. one who has not reached the age of 18 years; a minor.

[Fred Nerks]

dated August 22, 1968