Rabbits shouldn’t be fed pellets with extras. The extras typically no good for the rabbit and they also tend to avoid the pellets (which yours is doing). I’d start switching her over to a plain pellet such as Oxbow brand.
For hay, you could try mixing in another grass hay, such as orchard or oat, in with the timothy to get her more interested. Rabbits do like to eat hay while doing their business so I wouldn’t worry about that. Ox, my bun, only eats hay before, during, and right after going bathroom. I put his hay rack at one end of his litter box but I know other members on here put a layer of hay down in the litter box.
Hopefully another member can confirm this, but I believe you can slowly start introducing her to more vegetables at this age. I think the suggestion with that is to introduce one new vegetable a week so that you can monitor how well they do with it. If you go to the top of the page there’s a link called “Bunny Info” from there go to “Healthy Diet” and there’s a ton of info on feeding that should be helpful.
Also remember that carrots are treats and should be fed sparingly.