Welcome back ladies and gentlemen of the internet. When it's someone's wedding, it's obvious to just respect their wishes for the wedding they want. Some people don't want a plus one, some want everyone to wear a certain color, and some don't want any children to attend. In my humble opinion, all these reasons are valid. Although, there is a line that goes from valid expectation to bridezilla.
In this Reddit story, the original poster (OP) is the bride who wants her wedding to be child-free. I can really relate to this; it can be so distracting to have young children at any event, and what if they cry during the vows? So all her guests seem to be fine with it, except her cousin. She shows up to the wedding with her one-year old. Not only did she fail to get a reliable babysitter, but she didn't even tell the bride ahead of time. I would probably kick her out too, on the sheer disrespect that she didn't say anything in advance. What did she expect to happen?