I'm sure there are still some things that don't quite make sense from this scene.
Basically, what happened is:
1. Mark crashed through White's window.
2. He threw bombs at her.
3. White transforms to bat and back again instinctually, to instantly heal the burns/explosion. Suddenly having bat-wings is not good on a night-gown.
4. Mark uses the smokescreen to hit her with the poisoned dagger
5. Not realizing the dagger actually means something, she hits him with a disenchant, killing his "color sight" spell/illusion.
6. The entire room suddenly looks different. Less dark. More... normal and home-like. She looks different. Younger and less witch-ey. She's in her night gown of all things. (Now torn and burnt for obvious reasons) NOT the almost cult-ish garb she appeared to be in previously.
7. She is actually a were-bat, but comments that that should be obvious... so obviously shouldn't be a problem. It's not like she was hiding it from the other Magi.
8. The poison becomes a bit more obvious when she tries to shift-heal the dagger wound... and it doesn't work.
9. She quickly realizes what it is actually doing... it seems to be trying to split her from her were-self... (something that has not happened before, as far as she is aware, but she also has Sight, and centuries of experience)
10. She is looking at all of this from a very calculating standpoint. She doesn't know what exactly is going through Mark's head at this point, but she knows he was being deceived somehow with mind magic. She has had enough people/things try to kill her in the past, that she can be a bit more practical about the situation. She knows she wouldn't be able to stop him if he decided to just flee... so she decided to be a bit more threatening about it. If it happens to work out that he turns himself in as a result... all the better. Then the truth can come out.
11. She then obviously needs to focus all of her energy on actually surviving this situation.
12. Her survival is unknown.