Friend in trouble?

A friend of mine moved out on her own maybe a month ago. She's 19, and the guy she's dating is 38. She's known him for two months but let him move in with her. He asks her about how much money she's spent, he doesn't have a car, and she doesn't know his friends or family. Her mom is 41, and doesn't approve of him. She cut off communication with her mom for a while because of it. She has been saying she has baby fever with him and has hinted that she's afraid she may be pregnant. I'm decent friends with her but don't feel it's my place to say anything. Her closer friends have tried to talk to her but she doesn't listen. I'm afraid she may get hurt physically and/or emotionally. Should I say something or just keep tabs on her and let her make her mistakes?