Pride? Has nothing to do with pride, it has to do with a dulling of the senses. You are an inferior species in the regard of aesthetic pleasure, it has no point in Necron society. The lack of ability to smell, feel, taste, or enjoy makes for an empty existence where plain black bricks can be considered "perfect." For "females" there is no point in their existence for the Necron. In fact their design would be illogical in several regards. The first being a breast like shape would be a liability as the area between the breasts would focus projectile damage inward to the center of mass, making it tactically unsound. Also, Necrons are similar to Orks in their lack of gender. Of all the species you're closest to the asexual mushrooms, though in reality you are less than that, a genderless, soulless, non-race.
Well there are female Necrons if I remember correctly, but they have no physical differentiation with a male one. Necrons are simply Necrons.
That was sort of the point, there's no reason to differentiate. It's actually tactically unsound to do so. Also, there really aren't, seeing as they have no biology any longer, so they're genderless.
Of course female necrons exist, a race would not exist without male and female, also there's a female Phaeron (called Pharek) of one of the tomb worlds in lore, so really it's probably just a difference in voice and maybe some ornamentation
Gender has to do with how the mind works as well so of course what gender they were beforehand matters, at least for important necrons