Did Laverne and Shirley ever mention marriage in the show?

Yes, Laverne and Shirley did mention marriage in the show. In Season 4, Episode 8, Laverne and Shirley are both invited to separate weddings. Laverne is thrilled to be a bridesmaid, but Shirley is not as excited because she has never been a bridesmaid before. Laverne tries to cheer her up by telling her that she will be a beautiful bride one day. Later in Season 5, Laverne and Shirley both consider getting married while they are in Las Vegas. Laverne wants to marry a man she just met, but Shirley ultimately decides not to get married. In the end, Laverne and Shirley never get married on the show, but the topic of marriage does come up a few times.