Assalam Alikum. It is said that a miscarried baby would pull its mother to jannah. however if the mother is a nonmuslim,would the miscarried baby still pull its mother to jannah?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The statement that you referred to was mentioned in a Hadith narrated by Ahmad and Ibn Majah, and Al-Albani classified it as Hassan. It is related to the Muslim mother because such rulings are specific to those who died upon Islam and not others. Non-Muslims are prohibited from Paradise. Allah Says (what means): {Whoever associates any partners with Allah, Allah has forbidden Paradise for him, and his abode will be the Fire. And there are not for the wrongdoers any helpers.} [Quran 5:72]

Allah knows best.