While I would suggest she returns home for the delivery, usually airlines do not accept passengers after the 7th month of pregnancy. I would suggest you first get a report of her pregnancy immediately from a doctor and then approach some ticketing agents and see if they could get an airline to fly her back home. In the meantime, you could also visit the Women's Hospital for their for their views. Possibly, (and I repeat possibly) you may have to bear the costs of her delivery here as she is on a visit visa which may be very high compared to costs back home.
I suggest that those people who do not know should not misguide others. Writing just for the sake of writing can lead to painful, sad and tragic consequences.
Please do not abuse me for my above views as what took place in the past.