Musannaf Ibn Abi Shayba 9:562

Thaqafi narrated to us, from Muthanna, from Amr ibn Shu'ayb, from Urwah and Sa'id, who both said: Any woman who is married off for a dowry or a promise to her family that was before the bond of marriage, it belongs to her. And whatever was by way of a gift to her family, it belongs to them.