Was Mary sinless?

First let me quote Mary's words as recorded in Luke's gospel.  I am using the Net Bible translation. 

1:46 And Mary¹⁴⁶ said,¹⁴⁷

“My soul exalts¹⁴⁸ the Lord,¹⁴⁹

1:47 and my spirit has begun to rejoice¹⁵⁰ in God my Savior,

1:48 because he has looked upon the humble state of his servant.¹⁵¹

For¹⁵² from now on¹⁵³ all generations will call me blessed,¹⁵⁴

1:49 because he who is mighty¹⁵⁵ has done great things for me, and holy is his name;

1:50 from¹⁵⁶ generation to generation he is merciful¹⁵⁷ to those who fear¹⁵⁸ him.

1:51 He has demonstrated power¹⁵⁹ with his arm; he has scattered those whose pride wells up from the sheer arrogance¹⁶⁰ of their hearts.

1:52 He has brought down the mighty¹⁶¹ from their thrones, and has lifted up those of lowly position;¹⁶²

1:53 he has filled the hungry with good things,¹⁶³ and has sent the rich away empty.¹⁶⁴

1:54 He has helped his servant Israel, remembering¹⁶⁵ his mercy,¹⁶⁶

1:55 as he promised¹⁶⁷ to our ancestors,¹⁶⁸ to Abraham and to his descendants¹⁶⁹ forever.” 

  Every sinner needs a Saviour and in 1:47 above Mary says,"and my heart has begun to rejoice in God my Saviour."  She is stating that she is a sinner and needs the salvation that only God her Saviour can give her. Mary is a human being like the rest of us and needs salvation.  Of course she was a very remarkable woman in her response to what God was going to do through her, but still she was a normal human being.

  I believe Mary is horrified at the way she has been elevated by some.  Her words, above are full of humility.  She says her state is the humble one of being God's servant.. The mighty one has done great things for her. She knows she is carrying the promised Messiah and that in this way God has remembered all His promises to Abraham and his descendants. She exalts the Lord, not herself. We should do the same.