I don't think she is thinking that way or even close, for her I doubt there's a concept of "I am the one whose actions lead to their meeting". It's probably close to "That guy met my brother and he wants him, how dare he? My brother is mine alone." The fact is that she is the one dating Liu and she's the barrier between them, but.. not a complete one anyways. Only thing she is mad at her brother for, is the fact she knows he's lying to her sometimes and hiding things concerning Liu. We'll see soon enough, but I still think her brother is the most important person in her life and wants him all to herself. While the other guy is someone she detests and wants gone probably.
I don't think she hates her brother, but the other guy. Feels like she loves her brother (non-romantically) and is very possessive.