Ar-Rahman Ar-Raheem.

Glorious Quran : ROAD to Jannah

٢٥ يناير · 

Ar-Rahman Ar-Raheem.

This is, just like any other blessing from ALLAH, if the mother accepts it as a blessing from Allah. If she knows that the baby wasn't hers to begin with. It is about how she responds to her loss. Just like Hajj, we have to maintain such blessing.
When a believer accepts that which is from ALLAH in the greatest form of faith and belief that it came from ALLAH and not from anyone or anything else, the Reward is from ALLAH.
Read Holy Qur'an ; Surah Al Baqarah 2:155-157 where it mentions about being patient and reward to those on the right path.

"Be sure We shall test you with something of fear and hunger, some loss in goods, lives and the fruits (of your toil), but give glad tidings to those who patiently persevere.― (155) Who say: when afflicted with calamity: "To Allah we belong and to Him is our return." (156)They are those on whom (descend) blessings from their Lord and Mercy and they are the ones that receive guidance. (157)"

This also is for the father's. On the Judgement day, if the parents have accepted the loss of ALLAH's Will, and acted upon such,
The child which passed away until the age of puberty , will come to the parents and hold onto them until ALLAH accepts them both into Jannah.
Musannaf ibn Abi Shaybah 11882, Musnad Ahmad 27429, al- Tabarani, al-Mu'jam al-Kabir 305 (25:126)

There is support of this in the Qur'an, and through the Prophet Savs.

The mother's who would like there's a book called The Virtue of Remaining Steadfast when losing a child.
May Allah Guide, Reward and Have Mercy on each person that has left the loss of a child, and make us understand that we are not anyone's but ALLAH's. Some return sooner and some later , may we be among those that are righteous. Ameen.