If a woman gets her menses after Tawaf-al-Ifada Sahih al-Bukhari 329, 330
Translation
Narrated Ibn `Abbas
A woman is allowed to leave (go back home) if she gets menses (after Tawaf-Al-Ifada). Ibn `Umar formerly used to say that she should not leave but later on I heard him saying, "She may leave, since Allah's Messenger (ﷺ) gave them the permission to leave (after Tawaf-Al-Ifada)."