Does the sister know everything her brother did to sylhan???

I don’t think she knows everything BUT she may have caught on to the way her brother “eyes” him. Also the mc, who never asks for help, asking to take of her children and not tend to her brother ever again as soon as she got back was probably a pretty big sign as well. Put that along with his limping and the tension between the two… she probably knows her brother did something extremely dishonorable to mc I THINK