Momo's feed

At first I thought she was going to stab the sister and kill her as some sort of sacrifice but the last panel or two had me thinking otherwise. Like, it feels like she stabbed herself instead, at least to me. I think she is either trying to harm herself and make up a story that will put the main characters in a tough position and try and use that to control the duke or kill herself. Like, if she kills herself, because of the way she has the spell working, she will go back again and is trying to restart. Again. But I don't think she will actually restart, at most if she goes back it won't be very far