He was frustrated by not knowing her adult breast size whilst she was still a baby, normal fatherly ... devotion?
I'd say perfectly normal, yep. Nothing more
normal for a loving, devoted parent than to wonder about the size of their infant children's breasts and/or genitals.
Why, when I'd visit my sister on the maternity ward (nurse) I'd glance at the babies in the incubators and think "huh, I wonder how big their cocks will be when they are fully grown??"
Yep, perfectly normal fatherly/
PRESIDENTIAL behaviors.