Missed fasts during pregnancy

My sister in law is pregnant and so far has kept all her fasts, Alhamdulillah. She said that she has to keep all her fasts as she does not want to have to make up after ramadaan. I told her that I always thought if a woman is pregnant and doesnt eat during the day, the baby will be harmed. And I was told that a pregnant woman does not have to keep fast, and aso does not have to make up for it.

My colleague at work has a pregnant daughter, who is not fasting. She said that her son-in-law found out and she will not have to cover up, but pay Kafaarah?