Logan Wilson wasn't an assistant but the manager who was heading the excavation team in country A. He was expecting Alvin or Ean to arrive until he received a message that their lady boss was going with the little master.
Every last person working for Alvin knew that Alvin settled in Narnia after getting married. Though they didn't know the back story or knew the lady, most of them believed Alvin probably got married because of the baby. Thus they ended up assuming the woman must have been Alvin's one-night stand and expected the baby to be an infant.
Hence Logan Wilson and the security guards who arrived to pick up Anya were in shock. There wasn't an entourage behind Anya considering their wealthy boss. She wasn't the most beautiful woman or looked nothing like Alvin's flings.