During my time in a village, I assisted at a funeral, the man on the photo is writting down the name of the people who came on sheet of papers. Those will be put with the coffin at his final resting place.
You're almost there, but you've got wrong on some concept. here we're not talking about son in law or daughter in law, but this you can't find it out cause there's a character at the top which we can't really see, and it says "外“。 It stands for the idea that the people who actually came, are not close relationship with the mourning family. And one last thing, it's not zhao fang ruo, but zhao fang xi hehehe. Anyway, you've sorted it pretty well, and this wasn't easy hehehe ! well played. it's in hubei province, in a minority ethnic group called "tujia".