If it is a diet that you are comfortable with and there are no dangers to your birds, I would continue with that diet. If it is a diet that is nonvaried, add veggies and greens. It would be a good idea to question the prior owners about any special foods given to the pair during breeding season and when they were feeding their young. Most importantly, make the same foods available to the pair that they have had in the past when they are feeding chicks. Diet is another area you may want to speak to your vet about.
Veterinarians sometimes see trends in diet-related problems.
Not all breeders of conures will agree whether to change the level of protein fed during breeding season. I know breeders who had major problems with feeding high-protein diets to their breeding conures. I also know breeders who have fed, and still feed, high-protein diets to conure breeder birds with no apparent effect. I can only guess why results vary. The levels of protein in the diets and brands may be different.