I Lost My Little Girl Today

Hi...Is there anyone out there? My first post. I put my Female 16 year old kitty, Ralphie....yes Ralphie and a female cat to sleep this morning. She had cancer in her lymph nodes. She actually lasted longer than her Vet thought. My Grandsons named her when she was only weeks old. I rescued her from a field with a broken tail. My Grandsons were only 3 and 5 when we brought her home. They kept on calling her Ralph and she would come running to them. She would suckle on their necks and of course the got a kick out of it. They are now 18 and almost 20. How can I get my mind to work. I have another cat 17 years old and both girls cats have been together since they were both babies.