Okay, I can see where this could be an important plot point. Mom was an investigative journalist. She was working on a big, important article. Daughter finds the draft and thinks it's important enough to either finish and publish, or publish as is.
I presume the story is set in Canada, yes? If so, you might Google "intellectual property & probate & Canada" and you'll get some links to how intellectual property follows probate law.
As the others have said, at 16, she can't do much of anything. But her executor/trix can, so if the daughter is on good terms with an older sibling or her father, or whoever was named in the Last Will, they can work with the magazine/newspaper to get the stories published. Likely, if Mom was a professional journalist, the paper/magazine would probably take the draft and notes and would assign someone to complete it--especially if she was a regular.
Now, if Mom had no Will, it gets trickier. In that case, daughter should talk with whoever the nearest adult is (parent, sibling, aunt/uncle, grandparent) and talk to an attorney about transferring the intellectual property rights. That's the quickest, most logical thing, plot-wise. You don't have to go into detail in the text. Just have her looking in a phone directory for a probate attorney and set an appointment. Next chapter, they've talked and worked out who to call at the newspaper/magazine. The legal details are unnecessary for the plot.