Oslo around 100 years ago

This photo was taken in the same apartment I knew as my grandmother's apartment in Oslo. She rented that place for about seventy years!
It wasn't big - a small kitchen, a bedroom, a living room and a small entrance hall. The WC was half a floor up in the staircase and used by the two families living on that floor.
This photo is probably taken after they had lived there for about four or five years.
There is my grandfather and my grandmother and their two eldest daughters. My father was only born around ten years later.
The old lady is my paternal greatgrandmother. She used to live in a village on the countryside and had become a widow fairly young.
Now she had moved in with my grandparents in this small apartment in Oslo.
The young lady standing in the background "looks " like a relative, though I don't know who she is, at the moment.

It is interesting to note the many objects my grandparents had managed to buy or get for their apartment.
Next to the baby, on the table, is a photo of what seems to be my grandparents with their oldest daughter as a baby. True?