The title refers to the classical bridal march commonly called Here Comes the Bride which is from the "Bridal Chorus" from the opera Lohengrin, by German composer Richard Wagner.
Christy having the last name Bower would mean she's part of Angela's ex- husband, Michael's family. Although her last name is not mentioned during the show she's only credited as Bower. Mona implies that Christy is her sisters child. Christy's mother could have married a Bower like Angela.