If a mother has a miscarriage at 9 weeks and the doctor indicates the fetus stopped developing at 6 weeks, will the child in this case attain Paradise?
Bismihi ta'āla
There are numerous narrations that speak about a miscarried child and how our Prophet (s.a.w.) will boast about his ummah, even a miscarried fetus. Narrations mention the baby will intercede at the door of Heaven for its parents, and so on.
Please read this book: Soothing the Heart of the Bereaved, by Shahid al-Thani
And Allah knows best