Hi and welcome to Binky Bunny!
First off, a healthy bun will act like it is starving. Rabbits are extremely food-oriented, and that is normal.
For a baby bun like your Toffee, the House Rabbit Society recommends unlimited pellets, preferably alfalfa-based. They also recommend unlimited alfalfa hay. It is however good to try and get the bun to eat grass hay (such as timothy) at an early age, because grass hay is fundamental in the adult bun’s diet.
(Alfalfa hay is yummier though, as you seem to have noticed 😬).
White chalky residue or cloudiness in the urine means the rabbit is getting rid of the calcium it doesn’t need. Contrary to most other mammals, rabbits absorb all dietary calcium, and then the surplus gets filtered out by the kidneys and is peed out. This is the way it is supposed to work. We often see cloudy pee eith young buns due to their diet being extra high in calcium. Calcium is, as you know, important for many things, like the skeleton, the teeth and the muscular function. Your bun is growing rapidly now. I’d not worry about somewhat chalky pee right now.
So, to conclude: wean her onto pellets again, but start with a smaller amount spread out over the day so she doesnt pig out completely and get a stomach ache. Let her have grass hay 24/7 and serve her water in bowl, because buns drink more from a bowl than from a bottle. To encourage her to eat more hay, you can serve it in smaller piles in several places in her area. Many buns like to chew on hay when they go to the toilet, so its good if there is hay near the litterbox.
You can of course order more alfalfa hay and mix it with the grass hay.