She was a Jewish woman who had died. The Prophet ﷺ heard them weeping over her and said, "Her family is weeping over her, while she is being punished in her grave."
حدثنا هشام بن عمار حدثنا سفيان بن عيينة عن عمرو عن ابن أبي مليكة
إنما كانت يهودية ماتت فسمعهم النبي ﷺ يبكون عليها قال إن أهلها يبكون عليها وإنها تعذب في قبرها
[Sahih] Ahmad narrated it, 6/138, from the hadith of Abdul-Jabbar bin Ward, from Ibn Abu Mulayka, with the same wording, and in it, "The Messenger of Allah ﷺ only said this about a disbelieving man, that he is being punished while his family weeps over him." The hadith of Hisham bin Ammar has supporting narrations in Bukhari, no. 1289, and Muslim, no. 932, and others.