Stealth
“If they saw you, you were already too slow.”
Stealth is not a tool she uses. It is where she lives. Everything else in her kit is built on being somewhere nobody expects, at a moment nobody planned for. A rogue who gets seen first has already lost the only advantage that really matters.
So she moves slowly, reads patrol paths before she reads quest text, and knows exactly how close she can get to anything before it starts to wonder. Some dungeons she has cleared without most of the trash ever knowing she was there.
In practice: stay stealthed between pulls, learn the patrols, and never walk where you could creep.