4.3.1
in this scene olivia is giving her self to sebastian. she tells sebastian that he should marry her. sebastian does not really know wshat is going on but becasuse he is taken away by her beauty he agrees and they are to get married.
4.3.4
that they may fairly note this act of mine
to me this quote means that what she has done she knows that know one else has done it. she feels that she should go down in history. she wants people to know what she has done so she wants them to make a note of it so other can look at her.