Purity: Ghusl for Touching a Stillborn or Deceased Mother
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 513:
If a child is stillborn, his mother must perform this ghusl based on obligatory precaution. If [a child is born alive but] his mother dies, the child must perform this ghusl before reaching the age of legal responsibility based on obligatory precaution.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)