"The way the Church in Sunbury-On-Thames is designed, there are balconies on the second floor that has a direct view of the seating area. There was a nun there. She was staring daggers. She probably thought I was looking up NSFW material during my grandma’s funeral."

The presence of a nun would indicate that this is a Roman Catholic church. 30 seconds of Googling reveals that there is precisely one Catholic church in Sunbury-on-Thames: St. Ignatius. St Ignatius is a lovely little church in the Victorian Gothic Revival style, but alas it has no balconies. Gotta do better research before you submit these writing prompts, bud.

Also, I'm guessing a local would just refer to the town as "Sunbury," or at the very least wouldn't capitalize the "On" in Sunbury-on-Thames.