Sorry to hear it. Our German Shorthair needed to be put down last year and after 16 1/2 years, it was tough. Lucky for us, we still one only 8 years old to help out and keep the smiles.
So sorry for your loss but you see her again at rainbow bridge when you pass. I lost a lab/retriever mix this year she wads 14 1/2 so i know it is not easy but since she was sick you did the right thing putting her to sleep God Bless !!