razors Firstly, so sorry for your familys loss, its truly heartbreaking.
My niece died in April 2005, she was 19 months old. My SIL received cards to her, Dh and their new baby Dd who was born 8 weeks after Freya died. Sil refused to put up any cards as they didn't include Freya, 5 years on she always writes cards and includes Freyas name in them.
Everybody is different in how they deal with their pain, talk to your sister, don't ever thin you are hurting her by talking, she hurts already, remembering your niece is the best way to keep her with you.
Every christmas eve Dh, myself and our Dc visit Freyas grave, Dd draws a picture or makes a card, we take an ornament and flowers, and a card just to her to include her in our christmas.
We have a lantern and special decorations that we put with a picture of Freya on her last christmas with us.
I hope you all have as peaceful a christmas as you can, take care. x