IIRC, Nova picks her up bodily and carries her (and Kram).
And seriously, there's a phone at their apartment - Chris left a message on it, and they talked before Emma left to find Terra. If they call on the way to the apartment, there won't really be time for everyone to get there, sit down, relax a bit, and start talking about what's happened before Chris and Riese arrive. On the other hand, if they call when they get there, there's plenty of time for that, plus Kram and Idris' talk, etc.
Makes me wonder how big the apartment is, and if their complex is leasing. =/