Umm Ja'far (may Allah be pleased with her) said that Fatimah, the daughter of the Messenger of Allah (peace and blessings be upon him), said: "O Asma'! When I die, you and Ali bin Abi Talib should wash me together." So Ali and Asma' (may Allah be pleased with them both) washed her.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6660