I'm so sorry to hear you lost one of your puppies. Don't be so hard on yourself though, it's not anything you did, you took her to the vet and you have the others on medication, but a bacterial infection can come from anywhere and puppies are small and fragile. Pinky was already weak, and so couldn't fight off the infection, poor baby. I'm sorry for your loss Hun, and send love and prayers your way, and to the puppies that they heal from this infection and get stronger each day. This is not your fault , it's just something that happens. RIP Pinky.