Need help with children and religion

My step daughter 6 years old has recently started going to church with her mom on sundays. Not every sunday because mom doesnt go every sunday. Its something new her mom is into and they go when they can.

I never grew up going to church and my aunt would make me go if i stayed the weekend or was there on Sundays . My grandma lived with my aunt and uncle and she would watch us but if i was there my aunt would still make me go. I always felt uncomfortable going but didnt say anything because my aunt wasnt the nicest person when we were little. I also really didnt want to start problems between anyone and in my head when i was little i thought it would.

Anyways my SO and i arent religious at all. Yesterday my step daughter while we were in the car asked me to pray (actually say it and do it). I thought she said play but then she told me again. I told her i have never done it before and that she can say one if she wants to. She wanted me to but i told her i dont do that but she kept insisting. My SO finally stepped in and told her not all people pray and some have different relgious beliefs and that we cannot force our own beliefs and what we do on other people. She seemed rather confused and asked why because at church they tell her that praying is good and that good people pray. Im assuming since she is 6 she took it that because they say praying is good that only good people pray. Neither of us believe that the church or the people there told her that only good people pray and believe that she just mistook the meaning of what was said. I normally handle situations very well with her but i really froze on this one just because it makes me so uncomfortable to talk about that stuff. She really seems to enjoy church so i dont want to discourage that for her but im unsure how to handle situations when things like that come up where she wants me to participate in something im just not comfortable doing. Is there some way i can explain it to her that she would understand that its ok for her to partake in that stuff if she wants but that me and her dad dont do that without making her feel uncomfortable doing so with us. We are definitely ok if she wants to pray before dinner, bed, or just whenever she feels like it.

My SO and i fully support her going to church and being part of it if thats what her mom is doing and she likes it. We will never discourage it but it is just not something for us.