A curious question

So here is a curious question that begs an answer. I was in the Eaton Center and I came across woman who had her head shaved sitting next to a Muslim woman wearing her head scarf. Okay are you starting to see where I am going here. So the question…if a Muslim womsn shaves her head does she have to wear the head scarf since they are no to expose their head to the public. No I am really looking for a serious answer here. If you have one please post. I may check this out with an Iman at a mosque. The answer would help me with a group of characters I have planned for a story.