A.T. Robertson Commentary Mark 5:42

"And straightway the damsel rose up, and walked; for she was twelve years old. And they were amazed straightway with a great amazement." — Mark 5:42 (ASV)

Rose up, and walked (ανεστη κα περιεπατε). Aorist tense (single act) followed by the imperfect (the walking went on ).

For she was twelve years old (ην γαρ ετων δωδεκα). The age mentioned by Mark alone and here as explanation that she was old enough to walk.

Amazed (εξεστησαν). We have had this word before in Mt 12:23 and Mr 2:12, which see. Here the word is repeated in the substantive in the associative instrumental case (εκστασε μεγαλη), with a great ecstasy, especially on the part of the parents (Luke 8:56), and no wonder.