Which raises the question: why? Why would Kaede not be in town? Why would Kaede block her magic?
Well, she doesn't think there is a way to answer the second question with the information she's got. She could speculate that Kaede is watching her as a test of character or something... but that sounds far-fetched. And if this is some sort of manipulation it's one meant for her to believe that Kaede is not in town.
And to the first question. Well, the most likely thing was that something came up. Something that prevented Kaede from sending back a message even thought that sounded fairly trivial with that absurd well of power.
And with that much power at her disposal, Temperance can't conceive of anything that could keep her occupied for too long. She could just ask to use the restroom, send another message and have enough time to spare to actually use the restroom. In theory it isn't inconceivable that Kaede is busy in a fight or preventing a disaster that they can't solve with enormous amounts of magic, but... Kaede is hours late, in that time it would be easy to improvise something and the idea isn't likely in the first place.
This leaves a handful of grim possibilites. The most likely involve Kaede being outed as a metamancer. One in a thousand looks small, but less so if you have enough people, even less so when you remember that it isn't just a matter of pure chance. Temperance met Kaede because she was in a place that attracts mages and the High Consulate would have mages, lots of them.
The library is closing. Temperance says goodbye to the librarians and leaves. She doesn't go back to her hotel; instead she takes flight.
Maybe it's nothing. But if it isn't then there is a lot of power at risk here.
Temperance carefully composes the best defensive magic she can think of along the way.