Hi My 2 Year Old Daughter Hit My 6 Month

Hi my 2 year old daughter hit my 6 month old baby with the back of her foot on his front soft spot. It sounded just like giving someone a strong slap. Baby was asleep. He woke up but did not cry. I fed him and he went back to sleep. I havent seen any warning symptoms. Could this have an effect on his cognitive function even if he appears fine?