This is a refreshingly different question! Normally, any question about the character of Lady Macbeth focuses on her unyieldingly evil nature and the way that she bullies and cajoles her husband into his evil path. However, if we have a look at her character from a more positive standpoint, we can see that there are several positive characteristics that we can pick out.
Firstly, she is a character who, when she decides she is going to do something, is totally committed to that action, whatever the consequences. Note for example her impressive soliloquy in Act I scene 5 where she dedicates herself utterly and resolutely to the force of evil:
Make thick my blood,
Stop up th'access and passage to remorse;
that no compunctious visitings of Nature
Shake my fell purpose, nor keep peace between
Th'effect and it!
The overwhelming image is on the resolute nature of Lady Macbeth as she desires anything that can "Shake her fell purpose" to be taken from her.
I think as well we can say that Lady Macbeth is resourceful and is not afraid of getting her hands dirty. She is a starter-finisher, to use the paralance of modern business speak. She will see her plan come to fruition even if she has to get involved herself. Note the expertise with which she cajoles and bullies her husband to commit the crime, and then her own willingness to smear the grooms with Duncan's blood.
Lastly, she is able to present a face that bears no indication of what is going on inside of her, which is always a useful ability to possess. The way in which she is able to play the perfect hostess in Act I scene 6 is a perfect example of this. Therfore, analysing the character of Lady Macbeth reveals that she possesses a number of positive characteristics.