To add to Parvin, this usage of "duck" is still common in the north of England, among some older people, and would be less common among young people.
We have "bab" in Birmingham, used for both men and women in a similar way and is common even among some younger people, perhaps from their 30s.
They're terms of endearment. Older people can often use terms of endearment more naturally than young people so they may seem more old-fashioned than they really are.