According to an Ob-gyn from BabyCenter.com, being pregnant with a fever could be dangerous and could possibly affect the baby. It could increase the chances of heart defects, cleft palates, and etc. It's especially dangerous in the first trimester since its the most sensitive time of development of the baby, so at least your friend is in her second trimester but it still could be dangerous so always seek medical/professional help instead of just trying to cure it on your own! :)
You can read more about it here: http://www.babycenter.com/404_can-running-a-fever-while-im-pregnant-harm-my-baby_1246886.bc