ANSWER:
This is an age where teenagers tend to become rebellious. It is a blessing from Allah that she is not actually doing this but rather asking permission for that.
You must incubate her with love and compassion and explain to her through Islam and through logic how this would impact her life and the lives and honor of her family.
Teach her to know Allah’s beautiful names and attributes and to learn more about the sunnah of our Prophet and his seerah salla Allahu alaihi sa sallam.
Bit by bit, she will in Sha Allah remain steadfast on Islam.