I don't know what it is about medieval children's shows lately. You can't move without bumping into one. But FWIW, this is the worst of the lot by a considerable margin (in fact all the others are quite good).
Where to start? Well the real wrecker is the 3D animation. It's just ghastly. Ghastly, I tell you! Jane (who as you have guessed is friends with a dragon) moves about the castle with spastic, marionette movements that make it look like a student's demo reel, or some computer game from 1996. The voices aren't suited to the characters, though the dragon is passable. The lyp-synch is out. The best characters look alright. The rest look terrible.
And the textures! Not even the best of the characters or backgrounds could be said to be attractive, but they're also just so WRONG. The dragon looks like he's half astro-turf. Everybody seems to be made out of some different material, and the backgrounds are just... bizarre.
All of this is a shame, because the writing isn't too bad (it's not too good either), and would have lifted this show at least into the 'alright' category without being weighed down by the visuals.
Sorry, but this is just an ugly mess. It's profoundly depressing when you wonder if all TV animation might look something like this in five years.