Abdullah bin al-Harith (may Allah have mercy on him) narrates from Sayyidah Umm Hani (may Allah be pleased with her) that she said: When it was the day of the Conquest of Makkah, Fatimah (may Allah be pleased with her) came and sat on the left side of the Messenger of Allah (peace and blessings be upon him), and Umm Hani was on his right side. Then a vessel containing a drink was brought. He (peace and blessings be upon him) drank from it, then handed it to Umm Hani, and she also drank from it. Then she said: "O Messenger of Allah! I have broken my fast, and I was fasting." He (peace and blessings be upon him) said: "Were you making up a missed fast?" I said: "No." He (peace and blessings be upon him) said: "Then it does not harm you, if it was a voluntary fast."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21403