Five bucks says Catherine took Annette in because Heiner asked her to, probably to help her brother out of jail or something like that, and told her to keep it a secret. She's probably been keeping tabs on her for him this whole time and that's why she feels guilty taking the money. That's also probably what they were talking about for so long when he came to the house.
Where and when exactly would she learn about what happens during war or anything about how rotten the kingdom is? They don't have phones, TV, or internet and it's not going to appear in any books or newspapers she's allowed to read. She's probably monitored and supervised 24/7 and has guards and attendants that follow her everywhere she goes. Heiner is a jackass who's taking his anger out on the wrong person. This backstory doesn't make me sympathize with him at all, it makes me think he's deranged and dangerous.
So it's true - Catherine only took Annette in because Heiner asked her to and has been reporting on her to him this entire time. I understand why she did it, but imagine finding out the one person in the world you considered a friend was hired to take you in and has been lying to you this entire time. She's probably gonna feel really betrayed if anyone ever tells her.
Now he's probably going to have her reassigned or something so she can be moved from the frontlines. No way he just leaves her alone and lets her do her thing. He's way too obsessed to ever let her go completely.
As far as I remembered from novel. Catherine did not took Annette bcs of Heiner. She did call him at the beginning of Annette stay bcs she did not left her room as she was scared of other people recognizing her.
The one who needs therapy the most is you fkn weiner (⌒▽⌒)
Stay miles away from Annette (⌒▽⌒)