Does not naming my daughter after my friend, after I had promised her that at the age of seventeen, make me one of the hypocrites and cause me to incur sin?

A promise is a legitimate matter. Its ruling, according to the majority of scholars, is that it is recommended and not obligatory, but breaking it is disliked with a minor degree of reprehensibility (karahah tanzihiyyah). Some scholars held it to be absolutely obligatory, while others offered a detailed view: if not fulfilling the promise causes harm to the one who was promised, then fulfilling it becomes obligatory; otherwise, it is recommended. This latter view is closer to correctness. The Qur’an praised those who fulfill promises and condemned those who break them, and the Prophet, peace and blessings be upon him, considered breaking a promise to be one of the characteristics of hypocrisy.