Interesting! I’ve also heard the same as @georgia, that it can cause contractions of the smooth muscle of the uterus and induce a miscarriage. Maybe it depends on the stage of pregnancy? I’m not sure, and I’m not an herbalist, so I can’t even begin to say 
but you learn something new every day!
Pregnancy is difficult for a lot of people. It’s hard on the body and the mind, so that makes sense! If she’s trying all of the usual stuff – lemon, ginger, etc. – you could try a healing spell! Here are a few that could be adjusted to suit the needs of your friend.