I'm dealing with the same thing with my Holland Lop. This is the second time I've bred her and the first time wasn't successful. Today is 32 days for her and so far not looking so good. When I palpate her, she does feel plump and I can feel soft, oval masses. I'm not sure what to think about her.
"So I put a box in there Last week thinking maybe she'd start pulling fur/building a nest and she tore the box apart."
Mine rabbits don't usually start make a nest that early. Maybe it was just too soon. I've noticed that when I put the box in that early, it becomes a litter box. I hope everything works out for your girl.
I have a question about diarrhea. A girl in my 4-H bought a bunny from a reputable breeder. The rabbit was fine, eating, drinking, good droppings. I interacted with the rabbit myself, everything seemed normal. Her mom emailed last night saying the bun had really bad diarrhea. This morning, she told us that the bunny died last night. Any ideas on what could have happened? They were very careful with the rabbit, not letting it eat any strange or get into anything bad. As for mine, my rabbits get diarrhea quite often, even when there's no changes in diet. They have clean water, lots of hay, and a good quality pellet. What can I do to calm their stomachs?