It seems reasonable to assume along with the warrant on the home, a warrant for AA's cell provider would have also been issued. If that were the case, LE would already know exactly when, where, who, etc.
As for wherever they met up and took off from, that's a mystery. Where she was last seen at 3rd & University is a 10 minute walk to the Ferris Wheel, or a 5 minute drive to I-5 that would take them south to Mexico. Also, another 5 minutes down the I-5 and they're hitting I-90 at Dearborn, exit stage left (literally) and headed east to Moscow. To me, unless one of them was loaded with cash, heading back to Moscow makes more sense but who knows.
First I hope baby Seraya is brought home safe, but after that it will be interesting to learn exactly how they pulled this off (assuming we ever do learn the details).
jmo