Can you explain grandmother's grieving?
Thank you for your question. Grief and loss take many forms and are often unique to an individual as are the ways that individual chooses to acknowledge the memory of the dead. For more information about loss and grief, see http://www.extension.org/pages/9036/loss-and-grief#.Uouv7xXnbRY
For an answer to your specific question regarding why your grandmother acts as she does, you'll have to ask her.