Phoebe did not have the time to respond to Arrow's question and even if she did, she lacked the desire to talk about herself. She was not asking him about his ice magic and spells so there was no need for him to ask her about her magic.
Aside from Arrow, another curious person in the cave was Maureen. She knew Phoebe was really great with magic, but she had not seen her heal a person before. If she had known that her niece could insta-heal like a gaming character, they could have hunted more than they did.
She was literally a walking hospital so what did they have to fear?
"Hey, what's the deal with her?" Arrow took his question to Maureen.
