This is an interesting question as it draws attention to the way in which Olga as a character can be viewed in so many different ways and how she has the ability to divide an audience. On the one hand, she is the oldest sister of the three sisters in the title, and clearly her role is to act wisely and sensibly as she represents rationality compared to the other sisters. She is desperately trying to meet the code of nobility that her family have instilled her with, and as a result, she finds it very difficult to live in a world that is so different. She is therefore constantly in conflict and exhausted with the struggle. The way Olga thinks about Moscow shows that she is very nostalgic and that she is not able to look forward with excitement or anticipation compared to her other sisters and she thinks of Moscow as "home" even though they have not lived their for over ten years.
The way in which she struggles to see the purpose of her life when this visit is postponed could help us to see her sympathetically. For example, in Act II she is mostly not on the stage and lying in bed with "headaches" that seem to be a symptom of her struggle to face reality. In Act III, the way she speaks clearly reveals how she cannot deal with what is happening to her as she just moans and complains, using such phrases as "How sick of it I am" and "How terrible it all is!" This does seem to present her as a rather disagreable creature who makes us feel sorry for her.
However, if we examine the end of the play, it is possible to see her in a different light, as she finally comes to have hope and to be worthy of our respect and admiration. Note the final speech she gives at the play's close:
Oh, dear sisters, our life isn't over yet. We shall live! The music is playing so gaily, so joyfully, and it seems as though a little more and we shall know why we live, why we suffer... If only we knew, if only we knew.
This seems to definitely suggest that she not only has managed to integrate the of modern-day life with the strict old-fashioned code that she tries to follow but that she has also regained her desire to live and to engage in life once more showing her to be a kinder character. The two views depend very much on how you view Olga in the play.