No, Olga N. looked the most like her mother. She had the same allure, the same kind of silhouette, of face...I'm thinking of one picture of her, when she is sitting at a table and she's holding a walking stick. And here, on the website, when there's a bunch of pictures showing one after another, there is one of Alix sitting on a chair, and you can see the strong physical ressemblance of Olga with her mother.
Tatyana is more difficult to identify, though there are some pictures where you can see a ressemblance between her and Alexei. But to which of her parents she looks the most like? I can't tell...