Jennie
"Well. I don't know Runran very well either." 

He shook his head as Cuo's lack of confidence,"...I'm waging a guess you're much younger than I am. I've been working those magic muscles for perhaps, a decade or two longer than you. Fighting all my life. It is not appropriate to compare you and I's level." 

"If you keep working on yourself and tag along with someone unlikely to get you killed - that's not me, by the way. I'm sure you will learn Geomancy like me in no time. A lot of this is about building up, exercising the magical circuits inside your body - how much latent abilities you have inside you, you know?"
Catherine
"...I guess? I'm... I actually don't know how old I am. How old am I, Garuda?"

G-"Hell if I know. All I know is you found my book in the forest."

*Cuo looked disatisfied as she pitched a rock into the sky.*

"I've been training magic since I was a child. I've always been bad at it. It's thanks to Garuda that I've been able to progress to where I am now. I basically have no latent ability; magic or physical."
Jennie
"...Huh, you don't know how old you are?" Sirdan thought for a moment,"Do you have uh, any memories of your childhood or something?" 

Then he examined Cuo and looked her up and down,"All people have the potential for magic within them. Some stronger than others - just like how some are able to become greater warrior than others. But it is simply a matter of knowing a good tutor and having the resources to learn magic. If one day everyone in the world could dedicate hours everyday to study magic - then everyone in this world would wield them."