quick replacement

Installed several packages on April 5. physically released the queen on April 7. I had placed the package on 6 frames of drawn comb and fed 1 gallon of 3:2 syrup. Yesterday April 23 there is a beautiful Cordovan queen walking around on my frames, and no sign of my marked Italian queen. I saw no eggs, but Saturday she was there(April 19). I was looking to see if I needed to add a second box, not expecting this. Since it was full of bees, I feel they killed her or shes here and hasn't swarmed. This seems to be normal to packages is is because they aren't out laying and the bees sense she is failing due to lack of brood pheromone?