Okay I think I've replicated the bug or something very similar at least.
She died much further into the vanilla wad Map 10 with clusterfuck-v4.3.1
2nd death of her in the wad, and she went little bunny form. The problem is she's completely immobile (well hovering up/down in place) and does nothing except reacting with standard follow or stay lines when pressing e on her just like my first encounter.
Second, possibly related note when she's regular dead ie "I'm dead, move on" she also reacts with the typical follow or wait lines and when I call her it doesn't show she's dead it just does the regular call out, I only mention the above because, I had a peek at daisy's code and saw some lines from doom guy about her sleeping which I haven't seen at all unless that's not implemented yet. Also minor potential bug the caco demon pet if alive when she dies and goes little bunny or reagular dead dead it becomes a permanent party member for the level, dunno if that's intended behaviour or connected to the bug.