It is narrated from Ibn Abbas (may Allah be pleased with them both) that Sayyidah Safiyyah bint Umar bin al-Khattab (may Allah be pleased with her) was with the Prophet (peace and blessings be upon him) on the day of Khaybar.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21185