The logline would benefit from streamlining and refocusing. As currently stated, it seems to present 2 main characters with two different goals. The boy wants to be reunited with his father. The girl wants him to recover "something that is precious".
"Something that is precious" needs to be stated as something specific. But the fundamental issue is that the logline should focus on one main character as protagonist, another main character as antagonist (who is that in this story?) and one objective goal.
This is not to say the girl's story line doesn't belong in the story proper. But there isn't enough space to cram it in with the boy's story line. Ideally a logline should not exceed 30 words, certainly not exceed 40 words. This version is 47 words long.
And just as there should be unity in terms of the objective goal, so should there be a unity of theme. Consequently, her demand is not just a stipulation, a requisite means to his dramatic end. In some aspect it should also be thematically related to his goal (either contrasting or complementary). Which I presume there is the story. Ditto the relationship between the kidnapping and the boy's objective goal. The two should not only be causally related but also thematically related and I presume there it.
fwiw.