She'll definitely outgrow that litter box in a month or two (looking back, it boggles my mind how tiny Nala and Gaz were at 8 weeks old!)... which is a pity because that grid design that keeps them off the bedding is quite awesome.
https://www.rabbitsonline.net/threads/the-stormhaven-litter-system-step-by-step-instructions.48510/ <~~ this site has amazingly detailed instructions for making an adult size litterbox with the same concept (including a built-in hay manger, though you can always skip that part if you don't have the NIC grid and/or tools to make it). You basically need this stuff that's a light diffuser for fluorescent lighting (look up in an elevator sometime and you may just see some) - it comes in a 2'x4' sheet at Home Depot and such; you can cut it to fit any litterbox of your choosing.
As for the bedding, that ferret stuff will definitely work... but it's worth mentioning that you can get 40 lbs of
wood pellets (horse bedding) from any feed store for a little bit less than that 10 lb bag of ferret stuff from the pet store. It works just as well, if not a bit better.
Also, I remember well the obsessing done over those itty bitty baby bunnies!! Wow, was it all quite the experience. Everything seemed so high stakes, hehe. It's probably similar to having your first kid vs 2nd or 3rd. The baby book has to be just perfect, taking TONS of pictures, wanting to document everything and protect them from every tiny thing... I miss the cuteness but not the anxiety of being a first time bunny mommy
.