It is narrated from Sayyiduna Abdullah bin Sa’d (may Allah be pleased with him), he says: I asked the Messenger of Allah (peace and blessings be upon him) about eating food with a menstruating woman, so he (peace and blessings be upon him) said: Eat with her.
Hadith Referenceالفتح الربانی / كتاب الحيض والإستحاضة والنفاس / 953