不需要為小孩子的事情道歉。再說你家寶貝也沒錯啊?你又沒讓他家孩子摔,沒必要道歉。下次再遇到類似的,show 一下你的同情就可以了,比如說: Oh dear you poor little thing..It's such a shock isn't it?他的媽媽不是說他以前沒有摔過嗎?那你也說啊:It's so hard, isn't it?My little one is learning to walk at the moment and so wobbly too. Hope he/she wont have much fall either.
就事實說,不用特別抱歉。本來就不是你的錯啊。也別內疚。都是孩子,磕磕碰碰難免。