I would suggest against Maliyah because it is overused and MaCyn because it reads as though pronounced "mah kin" or even "m' sin" (like, my sin) and the poor kid will have to correct people all her life. (People know at a glance how to pronounce your other two kids' names even if they are a little unusual. Giving a child a name that is hard for adults to comprehend at first glance is to give her a name she has to continually explain, and that is hard for some kids.)
If you want the c or k to be in there with the M, try Miki or Miroki or Marcia or Markie, also there are Maeve, Miriam, Michaela, Maren.