Fiancee of the wizard?
its not that one
http://www.mangago.me/read-manga/sincerely_i_became_a_duke_s_maid/
the ML is not a mage but i found smtg similar lol
From Maid to mother?
Suddenly became a princess?
I think so too
thank u thats the one i was looking for, also thanks to everyone who replied .
it's a girl who became a maid after being reincarnated, the male lead is a black-haired mage