All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
It is permissible for a woman to breastfeed her child while in the state of sexual defilement whether by day or by night and she is not obliged to perform Ghusl (ritual bath) before breastfeeding. Performing Ghusl is only an obligation for the prayer, for performing Tawaaf (circumambulation around the Ka’bah) and other acts of worship for which purity is a condition.
Allaah Knows best.