What Can I Do to Secure Lowest Cost Possible for Maternity Care

I doubt she can get an insurance policy to cover it - at this point, it's a "pre-existing condition" and probably won't be covered. She can check with the welfare department and see about state or county paid prenatal care, but she may not be entitled since she is just visiting.

She may also want to consider that if her child is born on US soil, it is automatically a US citizen. Not sure if that would cause her any problems, but if she's thinking of staying here with the child, she should consider that if she is ever deported, they WILL NOT deport the child. The child will be a US cititzen and as such, not subject to deportation. I have seen many families where the parents are deported, leaving US born children behind who then are put in foster care.

This may not be the best idea for your friend. There are MANY other things to consider than cost!

Another option is to go to Planned Parenthood. They offer prenatal care and will know where to refer her for her delivery.

She needs to just wait. don't ask her to visit during her pregnancy. Let her stay where she is until she has her baby, then visit you later. I don't know why she wants to travel to the US JUST to have a baby. . . .
BUT regarding cost. She would have to be a cash pay patient and the costs to consider are pre-natal care, delivery costs for the doctor, labor and delivery costs for the hospital, hospital stay, medications while in the hospital, medications for the child in the hospital. that is just the basics. THEN she'll need to take into account anesthesiologist, anesthesia costs, and all the other things that could be billed (premie, NICU) and have some savings for that, too.

She needs to call the local hospitals and find out if they have any free clinics. Hospitals will often have them but don't publicize them. If you call and ask they will get some general information such as income and perhaps some medical details. Then based on her income she could go and do all that is needed to have a healthy baby.