Normally, this distinction between the two sisters should have been clear-cut and fixed, but it wasn't. At times, I had the strange impression that the scientist was in fact more of an artist than her sister, and inversely. But I never saw them as twins, because they remained distinct women, with contrasting personalities and behaviors. Maybe "complementary" would be a better adjective than "contrasting", because one seemed to possess what was lacking in the other, and vice versa. In any case, they were splendid sisters, each in her specific style, and I was happy to be their friend.
à la mémoire de Dominique