Grandmothers death left me numb

I lost my maternal grandmother about 3 months ago to lung cancer. I feel guilty and cruel as It has barely affected me though we were quite close.
Life goes on as normal for me, where as my mother and sister are constantly upset by things that remind us of her.
Is there something wrong with me?
I was upset the day of her funeral however that seems to be the extent of it,
I keep waiting for it to hit me like a ton of bricks, all these things people say you should feel. But I dont feel anything except guilt im dishonouring her.
Am I inhuman?