Great cages and setups. I wouldn't be too concerned about Flora's taming not going as quickly as you had hoped. It is still quite early for Flora and Mallow to be completely settled in to their new homes, especially since they had to adjust to the separation, new cages/setups, etc. Fiona will probably gain more confidence soon when all things are more settled. I would just give her a bit more time.
As far as Mallow is concerned, since she doesn't seem to react to any sounds/movements until your hand is literally touching her nose, I would just be extra cautious to not startle her because that may result in her nipping at you out of self defense. Just make all your movements slow and steady and let her approach your hand instead of the other way around. Good luck and have tons of fun with them.