Today I've got Alice's 7-year-old on the couch. She's an only child who grew up with her single mother and widowed grandmother, the latter of whom died 6 months ago. She wants to know what it's like to have a father and a family.
I think you can use the event of the grandmother's death as an impetus for Leanna's sudden interest in learning more about her father, but the death in and of itself might be harder to connect. I'd suggest having little Leanna witness something at the funeral, perhaps, that makes her identify strongly with the desire to have a father.
Maybe one of her mother's best friends is married and has a friend Leanna plays with, and these people come to the funeral. Leanna could witness her mother being comforted by the husband of the friend (nothing untoward here, just friendship), and her mother seems better able to deal with things afterward. In Leanna's mind, she absolutely believes that the only way for her mother to get through the death is to have a guy there to support her. What better guy than her own father, who has been rather mysterious for her up until this point?
The death of the grandmother could also prompt the mother to start looking through photo albums or something like that, and her nostalgia could be motivating force for the girl to look deeper into her father. But I think the previous scenario of her witnessing something at the funeral would work better as far as reader sympathy, poignancy, etc.
Good luck on this story, Alice! I personally love to include children in my manuscripts. There's just so much depth to mine with them.
Let's analyze: Anything else my readers can think of that would prompt Leanna's sudden intense interest in her father?