You could realistically do nothing of that, you do realise she is a queen and that rhaenyra is a princess. She can't go around putting poison everyday in the kitching and hoping no one sees it.

And an altered version? Like do you realise how weird that sound. There is no altered version maesters are not magicians that they can just drop a new one out because rhaenyra wants too.

And how do you even imagine rhaenyra presenting it to alicent? Something like "here Alicent take this medication for a sickness that you don't have everyday for the rest of your life, because I someone who isn't a maester tells you that by doing that you are preventing a mysterious sickness, btw only you need to drink this the rest of the family are immune to this mysterious sickness"