Sayyidah Asma bint Yazid (may Allah be pleased with her) said: I and my cousin (the daughter of my paternal aunt) came to the Prophet (peace and blessings be upon him) to give him the pledge of allegiance, and he (peace and blessings be upon him) said: "I do not shake hands with women."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20827