"Kateřina čeká rodinu s tamtím umělcem."

Translation: Kateřina is expecting a family with that artist.

[JBHayven]

Does it mean that Kateřina is pregnant or is it only literally that she is waiting for the rest of the family to come?

[endless_sleeper]

A) is correct.

For B), you would need to use čekat NA + acc.