If you had to put your dog down, would you stay with them?

My family will soon have to make the tough decision to put our dog down. (She has terminal bladder cancer). When the time comes, I want to be with my dog because I feel like she would feel more comfortable than if we were to just drop her off at the vets and leave. I know the rest of my family doesn’t want to stay because they think it would be to hard to see but I think our dog would be more scared to be alone… like we abandoned her. What do you all think?