I agree with pottergrl5. if she hadnt been brought up the way she had been, so privileged and meant to believe she and every other pureblood was above the rest of the wizarding community then she could have turned out nice.
However i do think that at her core she just wants a family and that really shows in Deathly Hallows when she and her husband betray Voldmort to look for Draco.