khun po khun mae mii 3 kon luuk. 

khun po khun mae mii luuk 3 kon

คุณพ่อ คุณแม่ มีลูก 3 คน

chan pen kon-kan kha.

For this one, could you please tell me what you would like to say in English. 

chan taeng-ngan lae yuu thii Singapore kha.

ฉันแต่งงานและอยู่ที่สิงคโปร์ค่ะ

This one is correct but please let me add one more word to make it smoother. 

chan taeng-ngan laew lae yuu thii Singapore kha.

We always say that (by putting laew(แล้ว) in the sentence) when a person told that she/he is married.