This especially gets to me because she just left home where her father yells at people when he’s angry.
From Volume 4 Episode 2: Remembrance:
Whitley: I heard Father shouting with someone in his study earlier.
Whitley: No, she’s already drinking in the garden. I think it was a man.
This implies that Weiss’ mother and father shout at each other, often enough for her to automatically assume the person that her father is yelling at is her mother.
In both of the scenes where Jacques is speaking with Ironwood, he yells at Ironwood. There’s the scene in Remembrance, and there’s also the scene in Taking Control, where it sounds like Jacques broke something made of glass (Ironwood says “You need to control yourself” after the glass breaks). Also, in that scene in Taking Control, notice how Weiss flinches when Ironwood angrily yells “Jacques!”
And, of course, he yells at Weiss in Volume 4 Episode 7: Punished and even slaps her when he gets even angrier.
Weiss doesn’t like when someone yells in anger, likely because she comes from a home where one of her parents frequently does such and occasionally physically lashes out when his anger peaks.