A reasonable explanation is she did that as her wedding gift to the b&g. I don't think she set out to one up anyone just because she's a 'guest with a camera', that's like the bartender getting mad at the guy that brought a flask to share with the groomsmen. If you're confident with your skills, no guest should able to get near the quality of photos as yours. Uncle Bobs are here to stay and you will get someone hunching over your shoulder during formals; it should be a given already. A lowly P&S or a rebel with a kit lens with a pop-up flash shouldn't even be worth worrying about.