Queen Sophia became Catholic after her marriage, during her honeymoon, and on a yacht off of Greek territory, so as not to offend the Greek Orthodox.
She considers it to have simply been a recognition of the Pope, not a conversion, as the only thing she had to learn was the Latin ritual/liturgy, since the basic Greek Orthodox/Roman Catholic tents are the same (with some differences) and her Greek Orthodox baptism is recognized by the Roman Catholic church.
They had two seperate marriage ceremonies to satisfy both the Catholics and the Orthodox.
I watched the Papal funeral today (even though I'm Orthodox, the pope remains one of our Patriarchs, and I believe in the need for greater Christian unity, and evenmoreso because of his international religious work and work towards Christian unity), and I wondered to myself what Sophia was thinking when she was listening to the Orthodox "Christ is Risen", the Easter chant, as her Greek-Catholic counterparts sang it after the Litany of the Saints.