I don't see why a niqabi is any more likely to make a child cry than anyone else. I actually find that assumption a bit insulting. And I do not think a "masked individual" is incompatible. I don't think there would be a complete lack of facial expression. Believe me, I dealt with many niqabi women in Kuwait, and it is very easy to tell what facial expression they have on even with the niqab. Plus, vocal intonation is just as important as facial expression, if not more, so I don't think the kids would be missing out.
Facial expression and interaction is an important part of the teaching process. To preserve your modesty when teaching children is utterly perverted and obscene in a way. It really shows an unnatural way of thinking. It is simply wrong to hinder the teaching process of the children just because of some twat following a ridiculous ideology and assuming that she tempts everyone. And then why apply for jobs that involve interacting with people if one is so concerned with preserving her modesty?
. If nothing else, it would give them exposure to something other than bland white Western culture, and would hopefully spark some educational conversation with the parents.
Oh yes women dressed like ninjas... Some culture they are being exposed to.... why don't you expose them to honour killings, eating dead relatives and suttee while we're at it?