I gather from Yukari's first speech bubble (in response to Reimu's question from the previous page, "Is that why you killed Cirno?") that she doesn't know that Cirno is not, in fact, dead. (At least, not physically. The state of her mind may be another story...)
Hakurei Reimu.That's cruel... For Cirno to die for such a reason...Do I have to remind you that this is your fault?Yes.