C.Ann
I am so sorry you have to do this. It is a difficult decision to make.
I work for a vet and see it about 2-3 times a week. It is very painless and an easy way to go. My boss gives the animal a sedative to relax them, and then he gives the dose of the "pink stuff" as we call it.
Hugs to you, and your family.
Stay if you like, but if you don't it is okay too. We never make people stay if they are not comfortable with it.
Good luck..
Lisa