不需要为小孩子的事情道歉。再说你家宝贝也没错啊?你又没让他家孩子摔,没必要道歉。下次再遇到类似的,show 一下你的同情就可以了,比如说: Oh dear you poor little thing..It's such a shock isn't it?他的妈妈不是说他以前没有摔过吗?那你也说啊: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.
就事实说,不用特别抱歉。本来就不是你的错啊。也别内疚。都是孩子,磕磕碰碰难免。