How conversations should go:
Person 1: Can I get you a drink?
Person 2: Sure! Ginger ale would be great.
Person 1: [goes and gets a ginger ale]
Here are some things Person 1 should not say: "You want some whiskey in that?" "Are you pregnant?" "Why aren’t you drinking?", etc.
Generally, what other people are putting (or not) in their bodies isn’t super great to delve into. There could be allergies, or an illness, or pregnancy, or sobriety, or whatever. If the person wants to volunteer their reason for not partaking, they will.