It's hard to explain the reason methodically, but if it's negative, she would add another sentence final particle at the end of the sentence, something like 出入りできればの話じゃないわ (or, this might be more confusing but 出入りできればの話じゃないじゃない). Of course the context is the most important key, though.
In your example, she seems to be asking confirmation; 話でしょ?.