In the tutorial you can see an "i" key in that room right after you can "mirrormake" if you press the "i" key while Palin is present the camera switches focus between Hannah and Palin, of course the controls still focus on Hannah, so don't get turned around. I put every key symbol in the tutorial so people would think, hmm, maybe I should press that. I could probably add in a small carving to show what the key actually does or add in an extra info mirror when I do some more work on this.
Yeah I did try the I key but It isn't much of an aid as ultimately the character collision is affecting Hannah so its hard to get the fire to not hit the walls. Otherwise I thought that the platforming controls were quite smooth and well done, with wall jumping being slightly difficult to pull off.
Getting Palin not to hit to the walls is supposed to be a challenge at some points, keep in mind that the exact position of the sym line can make a big difference and you can hold up or down to make a horizontal sym line. Some of the wall jumping segments in the second level can be very challenging when trying to stop Palin from colliding, but it can be done, I've double tested every mirajewel and glinting shard and they are all reachable, though they can be challenging. I noticed you commented on the wall jumps but I take it you have not reached a monkey bar section yet? Now that was the real challenge to pull off.
If you send me a screen shot of the exact place your stuck I can probably explain how it's done.