My mom did this before I stopped talking to her for unrelated reasons.
I view it as unnecessary, and purposeful. Most adults understand how to separate proselytizing from normal mention of background activity. E.g., "I was at church the other night" vs "I prayed for X and the Lord delivers!"
I'm supposed to believe that she really doesn't understand the difference? Or is it more likely that she doesn't respect my beliefs (lack thereof) and is micro aggressing?
Any questions about why I don't really want her around my kids?