You've accurately pegged her age, she is indeed within the 4-6 weeks range, I second Jbun's comments above. You seem to be doing fine. You can always add some goat's milk or a little bit of heavy whipping cream for the extra calories to the kitten formula but you will probably only be on that for another month or 2. Rabbit milk is very calorically dense. I'd push timothy hay for sure, and an alfalfa based pellet until about 6 months and see where she is growth wise. At 3-4 months transitional veg would be some cilantro, dill, basil, romaine, red leaf, green leaf to start at that time rotating in some higher oxalate greens like parsley & kale. Dandelion, plantain (the plant, not the thing that looks like a green banana), chamomile flowers, wild raspberry bush leaves, are ok to start @ this time as well, just be careful about the amounts of them, the first two have higher amounts of protein so decrease pellet amounts by half on the days you feed those.