Bilhah

Bilhah

בראשית ל:ג , וַתֹּאמֶר הִּנֵּה אֲמָּתִּי בִּלְהָּה

The Baal haTurim points out that the Rachel did not refer to Bilhah as her slave שפחה (as Sarah did when she offered Hagar to Avraham). This is because Bilhah was in fact, a daughter of Lavan (her father) from a concubine.

Lavan says “the daughters are my daughters” indicating all of Yaacov’s wives were daughters of Lavan.