[Gorthaur the Cruel]

I just had a thought I'd like to get out there. Now Galadriel clearly tells Frodo that, "Many things I can command the Mirror to reveal." So meaning she could let Frodo or Sam see the past, present, or future. But if she left the mirror to work for itself, it's the strangest and most beneficial vision compared to the prompted visions. So I don't think the mirror is unreliable (when compared to the Palantir) and dangerous if under Galadriel's promptings, but it is dangerous when it's used as a guide for arbitrary visions.
And we all know that Galadriel had to pass a test of pride. Could it be that she knew all along, through her Mirror, of the Ring in the Anduin and within Bilbo's possession but kept it to herself? Because she did hide her musings on what she could do with the ring. She even tells Frodo that not even the wise could perceive her thought more clearly (meaning her wanting the Ring) than he when he offered her the Ring. So is it possible that she let this all go on (hiding knowledge of the Ring's whereabouts but not pursuing it like Saruman) to eventually lead the Great Ring to her? Could it be that she also let these things happen (without telling the Wise of her knowledge/desire of the One) to maximize the lasting benefits of a world after Sauron (death of Smaug, Gandalf kills Goblin King and Balrog of Moria) just in case she'd choose to pass her test?