Hey, I just posted my response. Didn't you notice? Oh, wait, yours came first.
I did address the "brother of Moses" comment. It is not accurate, to be sure. In an earlier post of this thread I believe I mentioned that there are a few examples, actually, of men from ancient Egypt who did in fact bear the name Ms or Mss. Exactly how the vowels may have worked is anyone's guess, so "Moses" might be one example. We don't know for sure, so in the literature the name is typically written as Mese, Mose, Meses, and other variations. To be sure, none of these have any connection with the biblical Moses. That would be speculative nonsense, of course.
I personally am not sure what the name Ms or Mss would have meant in ancient Egypt, but it probably would not have meant the same thing as the root ms ("born of") in a name like Tuthmosis or Ramesses. The element ms is found in a very large number of Egyptian words, and alone it can mean such things as "calf," "boquet," "indeed," and even the verb "to bring, present" (Faulkner 2002:116-117). It likely has a myriad of other meanings, some of which might lend themselves well to a person's name, but to be honest I'm not inclined to go digging through my library or something as verbose as the Wörterbuch to find more answers. I'm too damn tired and it's time to get my beauty sleep!