In Order of the Phoenix, while Umbridge thinks Harry is under veritaserum effect, she asks him where Sirius is hidden.
Then,
- If she stills thinks Sirius is guilty and wants to kill Harry
- She should have interpreted Sirius using floo powder to get into Gryffindor Common Room as an attempt to kill Harry.
- Harry should have no idea where Sirius is, so there is no point in asking it.
- If she thinks Sirius is innocent, and a friend of Harry
- She should have interpreted Sirius using floo powder to get into Gryffindor Common Room as an attempt to talk with Harry.
- Harry may know where Sirius is.
- There is no point in attempting to capture Sirius if he is innocent.
So neither option makes sense to me. Why did she ask that question?