In a statement issued through British Transport Police, Emma's parents, Mark and Zoe Lifsey, said:
Emma meant the world to us. She was our much-loved daughter and a baby sister to her 11-year-old brother Jack. We are still trying to come to terms with the terrible incident on Tuesday afternoon and there are no words that can properly express how utterly distraught we are.
We would like to thank everyone for the many messages of sympathy and support we have received.
As you can appreciate, this tragic incident has left us shocked and devastated and we would ask that we can be left to grieve in private at this acutely difficult and sad time for us.