It's entirely up to you to decide if you want to go to say goodbye. I have been to see some loved ones and not others. I saw my first when I was about 12... some of my Catholic family side went in for the laying out at home in those days. There really is nothing to be afraid of. It will be peaceful. Nan might be a poor colour, not pink and rosy. Her hair may not be set the way she always wore it, but she will not smell, she'll feel cold.Her skin could feel a bit waxy.
But she will still be your Nan. The one who gave you special hugs or read stories in a certain way. The one who understood you when no one else did. She will be the same Nan that loved you and knows that you miss her.
I can be comfortable with myself, knowing that I did not go to see my Dad. I would not have gone to see my Mum at the undertakers but my sister needed to be shown where they were. I said my goodbyes to them when they died.
Some get closure in a chapel of rest, some get that feeling when they attend a funeral and some never feel that their loved one has left them at all.
So, if you go, don't be frightened, yes be sad but don't be frightened.x.x