Sayyidah Umm Atiyyah (may Allah be pleased with her) said: When we washed the daughter of the Prophet (peace and blessings be upon him), he (peace and blessings be upon him) said to us while we were washing her: "Begin with her right side and with the places of ablution."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21624