Alexandra was an unusual and in many ways a very sad woman, despite her admirable devotion to her children. Many of her eccentricities and problems were undoubtedly the result of the strain Alexei’s illness caused, but even prior to his birth she was considered a difficult, intractable person. However, while her advice and stubborn nature were certainly harmful, she was not the only person to blame for what happened to Russia.
Nor was she the only Romanov who clung to autocracy. Many of the Romanovs, including Nicholas II, were equally opposed to democracy in any form, believing firmly in divine right. Nicholas would have resisted the creation of a Duma even if he had never laid eyes on Alexandra. I think the difference between them and Alexandra was that other members of the Romanov family (with notable exceptions) were not desperate and deceived by charlatans like M. Philippe and Rasputin. Also several of them began to see the writing on the wall (impending Revolution) as time passed. They were willing to make concessions if only to save their own skin, Alexandra was not.
During WWI Nicholas did occasionally write to Alexandra telling her, basically, not to meddle. It is unfortunate that he didn't have the courage to stand up to her firmly and listen to wiser souls.
To give you an idea of how other Romanovs felt about the Duma here are a few quotes:
GD Konstantin Konstantinovich "KR's" diary - 8 Oct 1905
Yesterday's Imperial manifesto arrived by telegraph: it guarantees freedom of speech, conscience and association; the right of election to the State Duma is extended to those not included under the manifesto of 6th August…This important news produced a painful impression. It's the end of Russian autocracy. These new freedoms are not an expression of the free will of the sovereign power, but rather concessions wrenched from this power.
KR's diary - 26 Oct 1905 - Tashkent
...My companions and I support the autocratic principle, and entertain the hope that, if a large number of peasant representatives are returned to the State Duma, then it may still be possible to return to the autocratic model, which undoubtedly has the support of our peasant masses. This would be quite unheard of in the history of counter-revolution, but one very much wants to believe it could happen.
GD Xenia's diary - 27 Apr 1906 - St. Petersburg
(Describing the opening of the Duma)
...Directly opposite us were the members of the Council of State and high officials, to the left the members of the Duma, who included several men with repulsive faces and insolent disdainful expressions! They neither crossed themselves nor bowed, but stood with their hands behind their backs or in their pockets, looking somberly at everyone and everything...Nicky was delighted that he would at last be able to sleep properly - last night he couldn't sleep - he kept lying there, waking every few minutes with feelings of sadness and melancholy in his heart!
KR’s diary - 5 May 1906
The Duma's answer to the throne is - filth. The Duma is a hearth of Revolution.