I would start feeding the hive a frame of brood per week / 3-4 weeks (fresh eggs and capped brood) from the other hive(s) (transfer the nurse bees with it as well) and also order a queen. Otherwise, you are risking a laying-worker hive in no time. This is far too long of a time frame for them to be without a queen and once the pheromones dissipate fully, laying workers will appear.
Also important to keep in mind: adding only a new queen with no brood frames will make it very hard for the hive to survive as it will lack a young bee population that needs to be present to take care of the many brood-related duties.
Lastly, a hive does not necessarily have a break in brood rearing once it makes its mind to swarm. So, the lack of brood, especially for such a long time, may well be due to no queen rather than a virgin queen. My last swarm came out of a hive that had 12 (!) frames of brood at the time it swarmed.
[Addendum; Edit Note: I realized that that this was an older question, once I replied to it. I will leave my reply stand as it may be useful to someone else finding themselves in the same situation].