Swapping pellets from the normal type to a type designed for young rabbits is a good option - they'll be higher protein/fat but they are the same volume so you don't decrease the desire for other foods like you might by just increasing normal pellets. If she lives with others you can separate for 10 minutes so she gets the right ones or just stock one pocket with each type and hand feed to avoid jealously
Foods like carrots and fruits have high sugar content where as oats and seeds have higher protein - so I would go for the later if you are trying to build new muscle. I personally favour oats as that's closish to grass seed heads which are the sort of thing rabbits would naturally have access to.
Foods like carrots and fruits have high sugar content where as oats and seeds have higher protein - so I would go for the later if you are trying to build new muscle. I personally favour oats as that's closish to grass seed heads which are the sort of thing rabbits would naturally have access to.