They definitely didnt do it. She was strictly insurance for Johannes. Plus he was probably thinking that if she is young and pretty and people dont trust her to be the head she could marry a guy and still be the head and protect the family. But he knew that she was a strong person ig.
Actually we know that they didn’t do it bc rn she’s tryna nullify the marriage by saying that it wasn’t an actual marriage bc they never had sex. That’s why she needs the redhead, the old dude told him in a letter before he died that he’d never had sex with her so if the red head says that in court they can get the marriage deleted and save Jeremy
the first couple chapters i was wondering. did he really got married to someone the same age with his son? did they do the duty of a married couple? but from how smart the late marquess is. I just think he adopted shuli so she can lead the family until his son marry someone and finally it comes true and i'm so glad....