There is absolutlely no question at all that the Theotokos needed to be baptised, as did the apostles and everyone else. She is one of us. One reason why we sing over and over again `more honourable than the cherubim, and more glorious beyond compare than the seraphim`of the Theotokos is of course to praise her holiness, but really, I think it goes beyond this in that we are saying `look, here is this woman, she is just like us, and yet through her great holiness and obedience to the will of God she shows that it is our destiny to be `more gloriouis beyond compare than the seraphim` because of what Christ has done for us. Wow!` She is the great example of what we can attain if we accept the will of God for our lives. And yet, no one achieves salvation on their own. It is humanly impossible. Just like us, the Theotokos needs a saviour. That is why, without hesitation, one can reply to the OP that of course she needed to be baptised.