Hake's consort and the zombie miller

[GawainBS]

Hello

I tried all the options, I even choose the "wear the ring one day, you the next day" option, but I don't find it in my inventory, nor can I talk about it with the teacher in the Magic School. According to the dialogue, Rina still has the ring, but now I can't choose to buy it off her, or the round-ribbon wearing. I can only offer to get her another ring.
Any idea where to get one?

Thanks in advance!