I was so cute when I was little - doing stuff like that!
Aww, wasn't I cute doing stuff like that!
「そんなことするなんて小さい頃の私可愛い」
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I was so cute when I was little - doing stuff like that!
または
Aww, wasn't I cute doing stuff like that!
役に立つボキャブラリー
when I was little = 小さい頃
so cute = とても可愛い
doing stuff like that = そんなことするなんて
aww = あああ(可愛い!)
wasnt' I ~ = 私は~だったね!(付加疑問文)
ご参考になれば幸いです!