L2 visa - wife is eligible for IW but kid is not

Dear Community,

I need to apply L2 for my wife and 6 year old kid. My wife is eligible for IW (issued US visa before, never denied any US visa). When I fill the DS-160, I will add a family member for my kid and while scheduling appointment, I need to add a dependent in my wife’s profile. I hope I am correct here. However, when the questions for IW are asked, my wife is eligible for dropbox but I am not sure about the kid as it is his first time US visa. What can be done in this scenario? Can we still book an in person appointment even if eligible for dropbox? Anyway, since the kid is 6 years old, most probably he wont be required at the interview. Any help and guidance in this regards will be super helpful. Thank you.

Kids below 14 are IW eligible.