How is Mary Warren a dynamic character?

It's interesting to think of the rather timid Mary Warren
as a dynamic character in The Crucible, but she is.  She is timid
and defers to the wishes of the older, more forceful Abigail almost from the very
beginning of the play.  She's been compliant for the Proctors, but she's also been
rather lazy--as evidenced by Proctor's reference to the whip when she's a bit
disobedient.  When John finally gets her to see that she must go to the court and reveal
the girls' duplicity, several days have passed.  That shows her reluctance to do what
must be done, for she knows there is likely to be punishment for her when all is said
and done.  She tries to tell the truth, she really does.  But Abigail is simply too
strong, and she reverts to her timid, obedient, and following ways.  Her journey as a
character has come full circle.