Just wondering if the Embassy will send all three visas (one K3 and two K4s) out together under the same DHL Waybill... anyone know for certain?

I can't say for certain that one waybill will be enough. The best way to find out would be to call DHL or the embassy. I have a friend that works for FEDEX and he says pretty much whatever you can fit in those envelopes is cool. As long as your not trying to put a DVD player in there your cool. But it's best to double check. My fiancee had her visa and her sons in there. Good luck

I would think 1 envelope be enough. I will ask Tanja later today, her and her son are coming together, I think she only used one envelope but will confirm.

Each visa "order" might generate a separate envelope in their systems. And I suppose it is possible to have one passport done before the other. Definitely worth calling them and perhaps even the embassy. Because if they don't have the paid slip, you might not even get in for an interview.