Shia scholar mentions this marriage to be Mutawatir (mass-transmitted and accepted as authentic) in Qamoos Al-Rijal volume 12 page 216 I asked him about the woman whose husband has died, Does she spend her time in her house or wherever she wants? Imam replied: Wherever She wants, For All ‎‏رضي الله عنه when Umar ‎‏رضي الله عنه had died he came to his house and took umm Kalthoum السلام عليها to his house. The report is sahih