We know that Sayida Halimah Sa’diya (may Allah be pleased with her) died as a Muslimah and was buried in Jannat ul Baqi but whilst nursing our Prophet (peace be upon him), what was her faith then?
Imam Ahl al-Sunnah Ahmad Rida Khan (رحمة الله عليه) says regarding Sayidah Halimah bint Abdullah bin Harith (رضي الله عنها):
“She was honoured with entering Islam and being a Sahabiyyah” and further on he relates: “al-Imam Abu Bakr ibn al-Arabi has stated: ‘No wet-nurse nursed him except that she entered Islam’, then on page 55 of his book: “Divine Providence decided these names (the names of the Prophetic wet nurses) and selected these personalities.”
[Shumul al-Islam pg 52 & 54 & 55]
Note that some of the Arabs before the coming of the Prophet (صلى الله عليه وآله وصحبه وسلم), clung on to monotheism and shunned polytheism and were upon the remnants of the teachings of Sayiduna Ibrahim (عليه السلام) and were known as the Hanifiyyah. There is nothing to suggest that Sayidah Halimah (رضي الله عنها) was not from them.
Allah knows best.
Answered by Mawlana Ibrar Shafi