Allyria had a hard time controlling her magic at first. It was just as difficult as a toddler learning to read or write. There was no exact instruction how to maintain it. The magic anchored on her emotions and until now she's still trying to make it appear without hurting her heart over and over again.
She could even barely throw a fireball towards the barrel. Whenever she attempted to, it would take wing for several seconds and turn to smoke when it's almost close to the target, a literal poof.
Likewise, it didn't go easy for Denize. It was challenging to teach someone whose magic was her own phobia. There were times when she'd walk away, taking the time to breathe and come back when she was ready. More often than not, she distanced herself if she could. Healing from a trauma that scarred you the most isn't an overnight miracle and Allyria understood it.