I am just a country boy from Hampshire, but onward taxis would be more readily available from Liverpool St. at 1 am I think. There maybe a case for trying to claim for the minor element of transport from Liverpool St. to home address- does she have the receipt? As for the rest of it, I think it would be put down to force majeure, or Act of God or whatever expression they use. Just as if one goes by sea, one must expect to occasionally get caught in a storm, technical defects can disrupt aviation more frequently- you cannot take undercarriage or flap problems into LCY, and there is a lot of resistance to joining the compensation bandwagon every time something goes wrong. Good luck, and please report the outcome for educational use!