I agree, maybe if she's on stage doing her magician act, do the stage clothes, but on her adventures do the new pants, coat outfit.. Whatever the actress is comfortable with/in
This and Constantine seems to indicate a Justice League Dark movie maybe coming sooner or later, which I would love. Though there replacing Matt which irritates me intensely!!
SO, done a quick search on who could play her, In no particular order
Alexandria Daddario
Ana De Armas ( her star is rising so maybe out of there price range)
Emilia Clarke
Those 3 seem to be the top picks, here's some more that I found that would be interesting
Jessica De Gouw ( Huntress on Arrow)
Eva Green
Kate Mcgrath ( Lena from Supergirl..)
Anna Popplewell ( From Narnia)
Odeya Rush (Isreali)
Emily Rudd
Alice Dufour (French)