mercury poisoning and pregnancy?

Hello!

My older sister is 27 years old,a mother of a toddler and currently 6 weeks pregnant. The other day, without knowing she was pregnant, she accidentally broke an old mercury thermometer and afraid that her 3-year old would go and mess around in the area, she immediately cleaned the mess up with bare hands and the aid of napkins. She says she touched a tiny bit of mercury with bare hands but she immediately washed them again and again. She also disinfected the room and left the windows open. 2 weeks later, she found out about her new pregnancy. We asked the OB and he said that "we'll see" but he didn't look really alarmed. We asked our mum (we had broken dozens of mercury thermometers when we were children so she must be kinda experienced) and she said that as long as it didn;t stay on her skin for too long and as long as she never licked it or inhaled it deeply, we're okay. I dunno. Could she be poisoned? Should she ask a second OB opinion? Should she opt for abortion?