Women can pass HIV to their baby during pregnancy, delivery, or while breastfeeding. Rather than talking about what they have heard, she absolutely needs to get to a doctor to talk about this. Even women who do not have HIV have to see an ob-gyn, preferably before they even get pregnant. So she should be seeing and talking with her ob-gyn a lot right now.
There are drugs that can reduce the chances that the mother will give the baby HIV. Without the drugs, there is about a 25% chance the baby will get HIV from the mother in the United States. With the drugs, the chances can be less than 2%. However, if she is not seeing her doctor and taking the drugs now, she is increasing the chances that her baby will get it every day.
Also, there are other HIV drugs that pregnant women should not be taking. So that is another reason for her to talk to her doctor immediately.
This site does a nice job of explaining it:
http://www.4woman.gov/hiv/livingwith/pregn
ant.cfm
