Her project stalled with Dumbledore gone.
She knew the theory, had done the calculations, but couldn't find the right runic language, and couldn't shake the thought that there was something missing.
Something more.
So it stalled, and with the DA out of commission she was down a distraction.
She studied for her OWLs, all 12, constantly, but it wasn't enough.
She was sad, and tired, and stressed.
Snape noticed.
He said nothing, but when she walked into 'detention' to find five First Years waiting she just knew, Snape had noticed.
"...I guess I'm your new tutor."
