I agree. It would be nice to "find" a gun with no obvious owner, and no way to trace it to you, but if it's been used in a crime, it will eventually bite you. There may be a bullet with its rifling somewhere in a police evidence room. Too big a risk.
Since I’m feeling particularly paranoid today, here’s my two cents..
What if the gun was placed there by the cops as bait for one reason or another, they were watching to see who came along to claim it, and your innocent daughter came along, picked it up, and just started to walk away with it...could be a real mess for her...
OK, so I’m done with my paranoid fantasy for today, have fun!! :)