Someone asked for my recipe

What do you do/say if someone asks for your recipe? My uncle’s wife asked for my choco chip cookies and I made that from scratch tas she even told me upfront she’ll sell it to her “suki” kasi sure na bibilin sakaniya ‘yun at sayang daw kita.

Syempre I don’t like to share it to her or with anyone kasi pinag hirapan ko ‘yun. Can you guys help me what to do? Shy person din ako and hirap maka-no lol. I received a lot of compliments na my cookies tastes like Mrs. Fields.