Originally Posted by CM
True, but they could meet outside the Guild. Menora is on the move a lot, partly because of her Beast Blood and partly because she accepts a lot of jobs. After stealing and keeping Frost she tries to avoid staying in Riften for long periods of time because she doesn't wish to cross paths with Maven. Though it may appear that Maven doesn't care, ya never know. In-game it seems like she really doesn't care if the Dragonborn keeps Frost, but in story it could be completely different.
Karliah and Eclipse are in windhelm at the moment but might travel somewhere else. Depends on what happens in the RP.