I see.
So from what I understand here is a quick point form breakdown of your story so far:
MC - candle maker
flaw - naive?
inciting incident - twin being kidnapped
external goal - save MCs twin
internal goal - grow up? become mature? take responsibility?
antagonist - sorcerer
obstacle - monsters
ally/possible love interest/possible mentor - knight
main action - fight monsters and sorcerer
Making the brother a twin raises the stakes even higher really good addition.
Has the making of a well structure story and it sounds interesting as a fantasy adventure I would go watch this movie.
I suggest redrafting the logline to include: inciting incident, MC+description, external goal, main action, antagonist, obstacle and (if word count permits) ally/possible love interest/possible mentor.
I don't think this logline needs her magic powers mentioned nor the specifics of the knight, his abilities, personality and dragon friends, knight is enough to describe his character in the log line.
i.e:
After her twin is kidnapped by an evil sorcerer a candle maker with the help of a knight must fight the monsters in the dark realm to reach the sorcerer and save the last remaining member of her family.