The tense of each verb is different: the aorist, came, marking as in a single point of time the disciples' arrival, and the imperfect, they were wondering, marking something continued: they stood and contemplated him talking with the woman, and all the while were wondering at it.
He talked (ἐλάλει)
The imperfect tense, he was speaking. So Rev..
The woman
Rev., correctly, a woman. They were surprised, not at his talking with that woman, but that their teacher should converse with any woman in public. The Rabbinical writings taught that it was beneath a man's dignity to converse with women. It was one of the six things which a Rabbi might not do. “Let no one,” it is written, “converse with a woman in the street, not even with his own wife.” It was also held in these writings that a woman was incapable of profound religious instruction. “Rather burn the sayings of the law than teach them to women.”