In Shakespeare's Macbeth, Lady Macbeth is partly to blame for Macbeth's downfall.
- They both react to the predictions that Macbeth will be king in the same way, even though separated: they both instantly jump to the conclusion that killing Duncan is what will be necessary for the prediction to be fulfilled.
- When they do meet, they suggest in their conversation that they should assassinate Duncan that night while he is sleeping in their castle. Macbeth is still deciding, but Lady Macbeth is already certain.
- Macbeth decides not to kill Duncan, but Lady Macbeth talks him into it by using manipulation and questioning his manhood.
- But when Lady Macbeth has an opportunity to kill Duncan herself, she cannot go through with it.
- Macbeth can, and does, kill Duncan himself.
- Lady Macbeth just does a lot of talking and planning, but Macbeth does the killing. Furthermore, Lady Macbeth has nothing to do with the rest of the killings that occur--those are all Macbeth. She is shocked when he kills the grooms, and is unaware when he orders the killings of Banquo and Macduff's family.
Ironically, if Lady Macbeth would have had more to do with the later killings, Macbeth might have gotten away with them. It is only when Macbeth varies from his wife's plans or acts without her knowledge that he makes mistakes and creates suspicion.
Ultimately, I do not think you can give Lady Macbeth all the blame for her husband's downfall. I think she helped him along, but it is clearly his own responsibility as well.
Macbeth's ambition is not awakened by anything his wife does. Instead, it is awakened by what the witches tell him. So he is already ambitious before we even see Lady Macbeth.
In addition, Lady Macbeth does not force Macbeth to do anything. True, she pushes him towards doing evil, but he is the one who ultimately decides and he does not seem to resist very hard either.