Perhaps it wasn't the best for Irene to witness what Stanley would do to her father, but she wanted to put on a brave face the same way Arthur had done for her so many times in the past. She was unaware that when the mage had worked on her injury, her father left the room because he couldn't bear witnessing someone performing such a grim task on his daughter.
Even though watching him be put under a sleeping spell caused her insides to churn with worry, she trusted the mage because he had put her through the same thing.
There was a very real urge to cling to Leif for comfort as she might have if she were presenting herself as a girl. Having to hide behind men in fear was something she had grown into in the future she saw. In her present lifetime, it wasn't until that moment that she felt the urge to rely on others so much, especially in the way of emotions.
