I will start the story with stating that this happened back in 1992. I was in elementary school on an air force base when my father's mother (my grandmother) decided to move in with us to help my recently divorced father care for my two brothers and me.
After about two months, my grandmother complained about frequent and painful back aches. One morning I was eating cereal with my brothers when my father told my younger brother to wake up our grandmother. He came back saying that her false teeth are out of her mouth and she isn't moving. My grandmother had died from a heart attack. My father held me and my brothers and was crying (I guess I didn't understand the concept of loss yet). I looked at my father and said, "Weren't you supposed to take her to the hospital today?" My father stared at me with a confused gaze. He said, "How did you know that?" I stated that I was standing behind him when he tucked my grandmother into bed that night and she asked to go to the hospital in the morning if her back still hurt. My dad said that I was never in the room even though I described everything to the smallest detail. I believe that was an out of body experience.
The next time I saw my grandmother was when I was awoken one night (this was 6 months after my grandmother's death) and felt uncomfortable so I ran to my father's room to lay in bed with him. I turned towards the open bedroom door as I watched a white figure, it was the whitest of white, float over the doorway and stop and stare at me. This lasted a couple seconds and then she floated down the hallway. I felt a sense of comfort and felt right to sleep.
The last time anyone saw my grandmother's spirit was a year or so after her death. My father had deployment orders to Iraq to assist in Operation Desert Storm. Two weeks before his deployment date, he got very sick. My brothers and I were scared, we thought he was going to die. My father went to the hospital and came back saying that he got walking pneumonia where one lung is filled with water. Two days later I heard my dad on the phone with my aunt saying that he saw mom (my grandmother). He said that she appeared as a shadow the night before in his room and said, "Everything will be okay. This happened for a reason." My father's unit deployed a week later. About 3 days after the unit deployed there was no sign of his walking pneumonia.
After all this time there has been no more sightings of my Grandmother.
Seems like your grandmother came for a reason, and now that she knows you are all safe, she has moved on.
However, I feel that the bond is very strong, and (Almighty forbid) if any harm should come your way, she will step in to protect you.
For me, that is the most comforting thought.