Of course — Christ is “true God and true man.” What’s your point?
He cannot be true man if she, being sinless, were not truly of mankind and in mankind’s state. Easy for Him to be divine if his mother was, by special treatment, sinless; he would not be “one of us”, aka “true man”.
And if she were sinless by special dispensation (read: divine favoritism), then (A) she did not need a savior (see Luke 1:47, “And my spirit hath rejoiced in God my Saviour”), and (B) Christ is not the only way. Precedent is set: why then condemn all for original sin if it may so easily be wiped away without sacrifice?