Transcribing a videotaped will

Recently, a friend of my mother in law, Carolyn, asked if I could transcribe her mother’s videotaped will. I said sure. I’m a medical transcriptionist, though, and I’ve never transcribed anything like a will, so I’m not sure if there’s a specific format I should follow, or what. I’ve been googling around looking for information, but I can’t find anything.

She said it should be verbatim, including the occasional kids talking in the background. Does anyone know anything about this sort of thing? Should I do it in a format like this?

CAROLYN’S MOM: I, blah blah, being of sound mind and body, doodoodoooo, etc.

KID IN BACKGROUND: Give me my Barbie!

CAROLYN’S MOM: I leave my Legos to my second cousin Steve.

PERSON RUNNING THE CAMERA: There’s a spider on your forehead!

CAROLYN’S MOM: Shut the camera off!

Or is there another format I should follow? We’re in California if it makes any difference.