Muhammad bin Ishaq (may Allah have mercy on him) said: Sayyidah Fatimah (may Allah be pleased with her) passed away at the age of twenty-eight. She was born when Quraysh were building the Ka'bah, and Quraysh built the Ka'bah seven years and six months before the prophethood of the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) stayed in Makkah for ten years after his prophethood, then he emigrated and stayed for ten years. Then Sayyidah Fatimah (may Allah be pleased with her) lived for six months after him (peace and blessings be upon him), and she passed away in the eleventh year after the Hijrah.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19201