That is almost a correct translation. It should be egy nő, however, since it's "a woman" and not "the woman". Also remember that előtt has a long ő.
The difference between your version and the given one is the directional portion. In the given one, she jumps towards the train, ending up in front of it (elé - movement to the front). In yours, she is already in front of the train and jumps around there (előtt - remaining in front).
The English translation suggests that the woman is about to jump in front of the train, but hasn't done it yet - like the observer has noticed her intention just as she is about to act. Is that correct? Otherwise the English translation would be "A woman has jumped in front of the train" yes?