First of all, let me say I love your sight. My husband and I got married 15 years ago and it went off without a hitch, but I love reading about all the faux paus that others experience.
My story is about my sister's wedding. Although the wedding went fine, the night before (the rehearsal dinner) and the reception were a different story. At the rehearsal dinner, where I was the Matron of Honor and my daughter was the flower girl, EVERYONE attending (whether they were part of the wedding party or not) received a gift, except for my daughter. Now you try to explain to a four-year-old why she is the only one not receiving a present, not an easy task. My sister said they had a present for her but thought they would wait until the next day to give it to her. Mistake #1.
At the reception my sister and her new husband sat at the head table as if they were the king and queen. They never got up to greet guests or speak to anyone, they expected to be waited on hand and foot, and refused to leave the table at any time for any reason. I could take that, to a certain degree, but my husband, myself and several other family members took this as the time to decorate the newlywed's car. We were very careful in what we used and only did a small amount of decorating, but this was considered awful by the bride and groom. When they finally did come outside, after everyone had left, they quickly took all the decorations off the car, threw them in the lawn of the church and left.
The straw that broke my back was the comment my sister made several months later. When asked by a friend about how the wedding went, she responded with "it was beautiful of course, but thank God it wasn't tacky like K and D's (mine) wedding! I was stunned, our wedding cost 1/4 of hers so apparently if it is not a big show it is tacky. I have never forgotten that comment, only now can my husband and I laugh about it.
Does anyone else sense a strong bias from this story? It's like the OP went out of her way to paint her sister as a bridezilla just because her daughter didn't get her gift at the same time as everyone else in the wedding party. Leaving the decorations on the church lawn is the only thing I could see as being really out of line (and possibly calling OP's wedding tacky, if that actually happened and wasn't just gossip).