แปลว่า:We have children.
Firstly, I'd better just say that the correct form of your suggested sentence would be "We have a baby"
But following on from that, I had some other thoughts...
I have seen a fair bit of cross-over meaning between words like ลูก / เด็ก / ทารก. They all seem to span that general sense of baby/child/infant.
But perhaps in the context of this sentence, I feel that "child/children" is a better fit. For example.
In English, saying "Our family has 3 children" sounds more suitable, as opposed to "3 babies".
To me, my take on these three words is as follows:
- ลูก = child (used heavily within the family context and a parent's relation to the child)
- เด็ก = child (used in a more general context, not specific to a family, e.g., "I saw a child on the street")
- ทารก = baby (used in a more academic/formal sense, perhaps by a doctor, or a journalist)
So considering this, I can understand why Thais would feel that an informal use of the word "baby" (e.g., "my baby is so cute!") would equate more to ลูก as that word feels more intimate and emotional, whereas ทารก feels a bit colder and clinical :)