It's not my call as to the photographer. If I don't do it, they'll just ask another friend or family member.
I don't mind the idea of doing it, don't mistake my nerves about it as reluctance. You'll just have to take my word for it that a professional won't happen and it won't matter to them now or later. They're just those kinds of folks. I'm just looking to do as good a job as I can and if it justifies getting another camera toy, so be it