But she was working in the BSL-4 lab, and if I understand correctly WIV and SHC014 (coronaviruses) were studied in BSL-2 and BSL3 labs, when a close to BSL-4 lab was needed.

There is no mention of BSL-4 in the article, which really jumped out at me.

And their earlier research was done in BSL-2!

She was at the BSL4 lab. This is different than the BSL2 lab that was speculated to have leaked covid.

Aren't they included in each other like a matrioshka doll?

Doubt it. I'm curious where the BSL-2 actually was.

The new laboratory building has 3000 m2 of BSL-4 space, and also 20 BSL-2 and two BSL-3 laboratories.

https://en.wikipedia.org/wiki/Wuhan_Institute_of_Virology#ci...

But of course the WIV has a few other research centers there.