when you got a shock or a scare, you are suppose to eat this to give you relieve from the shock. my mum suggested giving my new born this because he went out the first time and was really fussy and could not get settled when he came home. we dont't have it so we can't be bother giving it to my boy. dont't know how effective. but i dont't like giving extra things to baby.
i think you can tell her 'experts say that XXXXX is not so good in long term', or give examples of your friend's baby took XXXXX then become dependent on it, got problems, etc... sometimes we have to lie. =X white lies. =)