Not just for weddings, a logo can also be made for a special event or occasion. Take for example this cute little birthday party for a girl turning two. Done by Lemiga Events, the concept was Sesame Street and the birthday girl's monogram added a touch of daintiness (because she is anyway a little girl).
The monogram was used in various elements like coasters, souvenirs, decor, aside from the invitations. Sometimes these inspirational things make you think of already having kids (wait, did I really think that?).