Witches are female spellcasters; puberty usually marks the onset of spellcasting abilities in this race of hereditary magic users.
Witches, when they bear children, are believed to always bear daughters (as sorcerers are believed to always father sons). Whether this is actual fact or a mere tendency is unclear.
Two known exceptions exist, both the result of a sorcerer/witch union, which would necessarily disprove one of the two concepts. Both Kristof Nast and Eve Levine and Christopher Bae and Diane Enright had daughters, Savannah Levine and Victoria Enright.
Sorcerers are also generally seen as being superior to witches in terms of power - much to the protest of witches, but this is likely due to the fact that sorcerers are far more organized and active in the supernatural community, being in charge of the Cabals and that sorcerer magic tends to lean more to destructive and offensive applications.
The rivalry between the two races has separated witches and sorcerers for centuries. The fact that witches and sorcerers recognize each other's races when eye meets eye does little to help that situation.