Is It The Spirit Of My Great Grandmother?

This story didn't actually happen to me. My aunty experienced this and she lives in Srilanka.

My great-grandmother died 3 months ago because of her old age and her illness. After a few days my aunt started to experience things and it was her first time encountering this type of issue. One calm and peaceful night (2 days after my great grandmothers death) my aunty suddenly woke up from her deep sleep, she told me that she was feeling watched by someone. Right then she heard a cup fall down in the kitchen and someone walking across the hall with a cane (my great grandmother used a cane, she couldn't walk properly). Now my aunty was very freaked out because she didn't know what or who it was.

Day 2

My aunty arrived from work very late about 8 pm and everyone was fast asleep. My aunt had her dinner and went to bed right when she dozed off she felt a soft hand stroking her forehead just like her grandma did and she went to sleep. The next morning she told her mother about everything and her mother started to cry because she knew it was her mother visiting them one last time! My family is very religious they believe in spirits and afterlife.

Day 3

My aunt and her mother were wide awake watching a movie and it was already 11 pm. While they were into the movie they heard a loud humming of a song that sounded like a lullaby. My aunt didn't notice the hum but her mother did it was the hum of a lullaby my great grandmother used to sing to my aunt's mother when she was little. To this day we really don't know what it is.