Based on her sighting of the nebula at the end, I believe it is hinted that TJ's experience was real. I think that the exact similarity of the nebula was to show TJ that her baby was indeed alive at the planet and only TJ would understand this because of the bizarreness of the situation .
However, I believe it would be considered both a spiritual and real event. It would be real in the sense that TJ's consciousness and thus her true self was on the planet as the aliens gave her the opportunity to see her child one time before they were indefinitely separated. However, I think the spiritual aspect of this involves how the aliens managed to bring the baby to life and transfer one's mind from its original body and assign it an identical one .
However, it may be important to consider that a since we do not know a great deal about the aliens, we cannot truly comment as to whether such a transfer would be because of a high level of spirituality or merely because of highly advanced technology. However, assuming that the occurrence was real, it seems probable that there was a spiritual element as the essence of spirituality would have been the reason for the aliens going through the effort of bringing the baby to the planet for its own well being.