Sadie Muckle (Muckle being her married name) was the daughter of the Dwarf Santini, a famous dwarf wrestler of the dwarf wrestling circuit. Sadie had been a dwarf wrestler herself with the moniker of "the Terror."
She was married to Charlie Muckle but their marriage had been falling apart because of Charlie's myriad problems, Sadie always comparing Charlie to her famous father, and her demands that Charlie change. So when Charlie Muckle disappeared, after putting out Maniac Marvin's left eye when he caught the man in bed with Sadie, she thought her husband might not return. Especially given that Marvin lied about what happened to Charlie.
When Adam Burgess appeared and realized he was Charlie Muckle, it seemed he might go back to his old life with Sadie but he decided she was better off without him in her life. Sadie continued with plans to marry Maniac Marvin after this. She got a divorce from Charlie but got back together with Charlie when he crashed the wedding.