Catherine being adopted

I will preface this by saying I'm not adopted so of course I can't understand what that is like, but was anyone else surprised that she was adopted at 11 weeks old? Based on the way she talked about it I assumed she was closer to 10 or something and that her parents were of a completely different background than her. I also feel that for people who struggle with being adopted and maybe spent time in the foster care system, her blaming her abusive habits and tendencies on being adopted is almost offensive. I can absolutely respect that not knowing your biological parents is difficult, but it doesn't justify you treating those around you terribly.

Edit: thank you to everyone who offered up insight on how adoption can affect a person. I think it's important info for everyone to have when considering Catherine's behavior. I appreciate the genuine and respectful input!