Are you talking about V11, or Normal mode? She starts with a Rotom in Intense mode on V12, which doesn't have Hypnosis.
Ribombee can take care of everything besides Chandelure, where I switched in Lycanroc. I used Draining Kiss as well to heal up, not just Dazzling Gleam. Mismagius can be problematic since Mystical Fire gets boosted on both fields, so it has to be either one-shotted (which should be possible if you use a Metronome and the field is already the Holy field), or it has to be weakened. Since she sends it in right after Chandelure when I had Lycanroc out, it lost half HP already. And Mimikyu can also easily be dealt with, since she uses her Z-move to turn the field haunted again, but which isn't effective, and then uses Shadow Claw to get it boosted, but the field can easily be cleansed before she attacks, so it does little damage again.
By the way, I'm not trying to criticize your strategy or anything like that, just trying to tell OP that they don't need to train up so many new pokemon for this gym battle. Using Normal types that way sounds interesting. When I once tried using Flash on Normal mode it didn't work out, because I wasn't using Normal types, so I kept taking damage while Flash didn't do anything.