But she did know her father. Until he left them when she was 5 years old right...? And if that is so then the lyrics fits very well, she have some distant memories. You know in the documentary light and shadow she speaks very shortly of her father, that he maybe liked to fish and stuff. It makes snece with those little memories since you can remeber some but not to much when you are 5.
However. Im not writing this to prove that ths song is for her father. Im just saying that I think it could be so cuz everything fits with the lyrics and the emotions. But thats just my thinking.