Musnad Ahmad 554:4

'Affan narrated to us, Wuhaib narrated to us, 'Amr ibn Yahya narrated to us, from Abu Zayd, from Ma'qil ibn Abi Ma'qil, that he said: O Messenger of Allah, indeed Umm Ma'qil missed the Hajj with you. He said: So she went out when she missed the Hajj with you. He said: "Let her perform 'Umrah in Ramadan, for an 'Umrah in Ramadan is like a Hajj."