From left, Tatiana, Anastasia, Olga and Marie around 1902. Notice how the "big pair" and "little pair" are each dressed alike!
I've mentioned the acronym OTMA a few times and wanted to explain what it means. OTMA stood for the grand duchesses - Olga, Tatiana, Marie and Anastasia. The grand duchesses were dressed alike, either all together or in their pairs, so it makes sense that they developed an acronym for themselves. In an age when even parents of identical twins are discouraged from letting their children identify too much as part of a twosome, it's interesting to consider what being OTMA, rather than Olga, Tatiana, Marie and Anastasia, did to the grand duchesses. But the evidence that survives suggests the girls saw no problems with it; they were devoted to their family, with the older girls refusing to even consider marrying outside of Russia later in their lives.