Chaima seems to be the French transliteration. In Arabic there are a number of variants :
Shayma' or Shaima' شَيْماء, Shima' شيماء or Shyma شیما, used interchangeably (for the same person). The consensus on
http://forum.wordreference.com/threads/shima.805619/ is that it from Shamah "mole" in the sense of "beauty mark".