Hello

The invited reading of Lady Macbeth is that of a "fiend like queen"
capable of "direst cruelty".

However, as cultural assumptions about women have changed i.e women
being brought into partnership with men, espcially in marital matters,
arguably so too has the way Lady Macbeth is represented.  Is there any
evidence to support the theory that Lady Macbeth was a supportive wife
who attempted to help her husband reach his potential and whose
motives were based not on personal gain but the fulfilment of her
beloved husbands ambition?

"...Macbeth?s wife was not in any way linked with the killing of
Duncan. Lady Macbeth was in reality a loyal and trouble-free person.
From an earlier marriage Lady Macbeth had produced a son, Lulack, who
was well protected by Macbeth and succeeded him until he in turn was
killed. In fact, "Lady Macbeth" is not her proper name, as Macbeth
means "Son of Life", or "of the Elect", which was not a surname.
Technically, she would have been addressed as "Lady Gruoch" in the
Gaelic language. Her name is also recorded in Fife, where she is said
to have donated land to a group of Celtic monks..."

Source: http://netmedia.co.uk/history/week-12/ 

" Lady Macbeth fulfills her role among the nobility and is well
respected like Macbeth. King Duncan calls her "our honored hostess."
She is loving to her husband but at the same time very ambitious, as
shown by her immediate determination for Macbeth to be king. This
outcome will benefit her and her husband equally. She immediately
concludes that "the fastest way" for Macbeth to become king is by
murdering King Duncan."

Source: http://www.angelfire.com/tx3/chrissandy1/caladymacbeth.htm

"..Lady MacBeth did have a conscience. She had committed a horrible
crime and knew in her heart she was wrong. The only way for her to
escape was to end her life. This was also her payment for taking
another's life..

Source: http://www.electricscotland.com/history/women/wih4.htm

"..LADY MACBETH, his wife - Lady Macbeth is a good wife who loves her
husband. She is also ambitious but lacks the morals of her husband. To
achieve her ambition, she rids of herself of any kindness that might
stand in the way. However, she runs out of energy to supress her
conscience and kills herself.."

Source: http://homepages.rootsweb.com/~maggieoh/Macbeth/l_mac.htm

"..Lady Macbeth can be considered a perfect wife. She may not be a
perfect person, but when viewing her as a wife, and only a wife, she
actually can fit this statement. She does many things that may benefit
her husband, and hence the reason to why this title can be fitting for
her place. Lady Macbeth understands her husband because their
relationship is so close. She encourages and reassures Macbeth when he
is most vulnerable. She is also loyal, supportive and protective.
While always being determined and strong, she shows that she is loving
and caring as well. What else could a partner ask for?.."

Source: http://allfreeessays.com/student/Lady_MacBeth-Perfect_Wife.html

Hope this fits what you're looking for..Let me know incase you need anything else.

It was Malcolm (Duncan's son) that called her a "fiend like queen"

Well he would - wouldn't he ?

After all he had imported an English army into Scotland.

If one forgets history and Holinshed (the source of WS's fabrication)
and just look at the play within its own context as a soap opera, then
you need to adopt the same viewpoint as that of the people it was
written for.

If it was actually written in 1606 then there would be a certain
amount of greasing up to that old s*domite James I.

There would also be a bit of doubt about the 'divine right' of monarchs
- Henry VII had a very dubious claim to the throne

My take, much contested over the last 30 years, is that Macbeth was a
competent warlord and that his wife backed him up by drugging the
guards and 'screwing his courage to the sticking point'.

Duncan was a dickhead for appointing his adolescent son as his successor.

Banquo was an opportunist - albeit for future generations.

Shakespeare was writing a soap opera for his own times, and, in order
to improve ratings he was getting close to the knuckle.

Consider the sub text as:
  'Killing your plonkerish king might look like a good idea, but it
can drive your (cherished) wife insane and lead to an invasion of
utter b*stards'

- note that as a descendant of Banquo .. James was not so legit.

Shakespeare liked to sail close to the wind.
( that or is very possible, he had a team of script writers )