In a Shimajiro educational book I saw a line similar to this: 

> 
> \_\_\_ちゃんが知ってる乗り物は何ですか？
> 
> 
> 

(the actual one had less Kanji but you get the point)

The question is why was ちゃん used here as a generic term. I thought ちゃん was used more for girls and くん for boys, and since I think the audience for Shimajiro might be more boys, why didn't they choose くん here? Or is ちゃん actually a more neutral term?