You're all good. Each batch is different, but you made beer. Letting it sit at this point is the right thing to do. As others have said, even a slight leak can prevent airlock bubbles, so don't sweat it. Leave it for awhile longer and check the gravity again. If it remains stable, bottle it up.
I should also add that your beer is no dud. Fermentation happened. Also, those printed directions kind of suck (in 99% of all kits). These boards are way more helpful.