Your creation is merely an extension of yourself; express your creativity and do what pleases you.
You need to understand the image you're going for. Are you trying to take inspiration from real life? Are you going for a more exaggerated appearance? Is your MoC suppose to exists in a BIONICLE related setting or does it have nothing to do with BIONICLE? Perhaps your MoC is meant to be a commentary on the sexualization of female MoCs.
There is no right or wrong answer. So do whatever you want. Just understand that if you want people to take your MoC seriously, you have to take it seriously as well. Sexualization works if that is your intent, but don't expect everybody to understand or see your vision. You may be criticized for your choices, but criticism is only beneficial if you are creating with the intent to improve.
So it's up to you, the creator, to be self-aware and understand why you chose to implement certain aspects of your MoC and to realize what is culturally acceptable and what is going overboard. You've got to have the strength to defend your work and not let others saturate your vision and dictate how your piece should look if you know their comments go against your intent.
Depending on what it is you wish to achieve, then a lot of the advice in this topic will be very helpful to you; but it might not be very helpful at all.