In the end she might help, tho'... We don't know the differences between the black and the white one besides the will thing.
Actually chatte, the difference between white and black, white is purely a cloned arifical human off Hashirama's cells. Black Zetsu however has a poriton of Madara's chakra and is a bit more fight capable, this is why he was used to try and kidnapped the fuedal lords. This is also why he was always more serious compared to the others.
In actuality, there have been 4 types of Zetsu:
-Spiral Zetsu- The first Zetsu, a prototype who did not come out complete, had the silly personality of Tobi, later bound himself obito permanently. Gradually faded away as Obito's body grew to maturity and the body of sprial zetsu became Obitos. Given the personality, this was the true tobi, but after Itachi Obito took full control and this zetsu faded away, some think Obito was "asleep" given this zetsu freedom of movement and also why he acted silly around others like deidara.
-Zetsu prime- the first white zetsu, the one who was always around akasktui and later half of his body was turned black by madara to make black zetsu. Was killed by Sasuke. Was purely a spy and intellengence and communication person.
-Black Zetsu- As mentioned, created by Madara with half of zetsu primes body infused with madaras chakra, made to be more fight capable and serve as an extension of himself for Obito while he was dead. Currently incapaciated by the alliance.
-White zetsu army- around 100,000 clones of white zetsu empowered by the cells of Hashirama in Yamato, served as an army for the akakstui in the 4th war. Nearly all are expected to have died.