Greetings, and thanks for the question.
Sorry to hear about Cream's condition. It sounds as if she had encountered either a flu, or an upper respiratory bacterial infection, which could have been secondary to an initial flu episode. Once you notice the green discharge from the nose, that's normally a sure indicator of bacterial infection.
In order for me to give you a thorough answer, I need a bit more information, please.
1): Approximately how much does Cream weigh?
2): What type of Penicillin did you give her (Procaine Penicillin G or the long-acting type with Benzathine)?
3): What was the length of time between injections?
4): Are you seeing any more discharge from her nose (and was the initial discharge coming from both nostrils)?
5): Does Cream seem to have any noticeable problems breathing, and if so, can you tell if she has more difficulty inhaling or exhaling?
6): Does she seem to be acting normally otherwise (as far as eating, drinking and overall attitude)?
7): Are you noticing any type of exercise intolerance?
Thanks for taking the time to answer my questions, and I'm looking forward to hearing back from you.