What is the ruling on a girl's supplication for her deceased mother to return, as she misses her?

Allah has decreed death for every soul. Allah the Almighty informs us about the wish of some of the deceased to return to the world to do good deeds, but Allah has informed us that they will not return to it. Similarly, the Prophet informed us that the martyrs in the Barzakh (interim realm) wish to return to the world to be killed in the way of Allah again due to the honor they witness, but Allah informs them that there is no returning to it. Therefore, it is not permissible for your fiancée to supplicate for Allah to bring her mother back to life, as this is an transgression in supplication.