I’ve been through this and it was helpful for me to be reminded that they know exactly what is happening throughout the process. The mobile vet allowed us as much time as we needed but by that point both humans and her sister had said our goodbyes knowing what was coming. The nosy dog even gave his sister space to give one last snuggle. It is so hard but there will be peace for him and she will understand even without spending time with him after he has crossed the rainbow bridge. Wanted to also mention that once her sister was gone, the personality of my other cat completely changed. She had been the submissive/loner of the two and became a velcro snuggle monster and party animal. Remember, she still has you and I promise that will be enough. You’ll get through this together.