That Isabel feels threatened when she sees Nova is quite reasonable considering the girl's power. She is equivalent to a Third Stage Junior Knight while Isabel is an Apprentice Magus in the Basic Stage.
Considering their basic strength, they could be considered equal.
Arthur didn't tell Isabel about it, he walked towards Nova.
The latter was calm enough, more often looking at Isabel with curiosity.
As a woman of Vera City, she admired her too.
On the other hand, the wolves looked at Arthur warily.
"What are you doing here?" Arthur asked her.
The young woman pursed her lips slightly before answering, "hunting!"
"Oh..." Arthur glanced at the wolves briefly and asked again, "do you come to this forest often enough?"
"Yes!" Nova nodded.
"Then what do you think is the really dangerous place?"