I've provided the context of what made me ask this question below, as it could just be that I am misunderstanding the passage.
If I understand correctly, the first person is explaining that their friend has a めがねコンプレックス because she was teased by one of her classmates about this when she was younger(she is in high school now). The second person responds saying that's childish (I believe referring to the complex). The third person then responds saying they are just a kid so it can't be helped.
「あの子、めがねコンプレックスらしいからね。小さい頃、同級生の男子にからかわれたとかで」
「子供っぽい」
「実際子供なんだから仕方ない」
However, they are all in high school, admittedly the person they are discussing is 1 year younger than them, so I'm not really sure that 実際子供 makes sense unless I am misunderstanding things.