Purity: Ghusl for a Miscarried Child
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 547:
A man cannot give ghusl to a woman who is not his maḥram. Similarly, a woman cannot give ghusl to a man who is not her maḥram. A husband and wife can give ghusl to one another.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)