There could be a number of reasons why it won't work, such as her phone being incompatible with the cellphone network in the country she has gone to, or their network being down at the current time due to any number of technical faults...
Also, your network may also be experiencing some lag as I have sometimes recieved text messages days after they were sent (in the extremes) and quite frequently several hours after on the same day...
I wouldn't worry - Any authorities where they have gone would have contacted you (they're not dumb they can find out who you are

) if there was any real trouble, and there have been no plane crashes on the news and there would have been...
Chris