I'm not sad about my grandmother dying.
Were you close with your grandmother?
No, I barely knew her.
It may seem like people expect you to have a strong reaction to the passing of your grandmother but the truth is that if you weren't that close to her not having a huge reaction in normal. You should deal with her death in your own way.
It's still kind of traumatic for others
That is true. You can try to console your family members who may feel more close to your grandmother.