Imagining the state of Gemma's corpse after being out in the elements for as long as she had been turned Hermione's stomach. She thought that Rodolphus would've taken better care of the disposal of his murder victim than that. Didn't he promise her that he would take care of Gemma before his brother found her? It was possible that that was just another lie in a long line of them. Rodolphus probably had every intention of blaming Gemma's murder on Hermione from the very beginning. While she would admit to partial responsibility because she did ask the wretched woman questions that Rodolphus didn't want her to know, she wasn't actually the one who muttered the curse.