There is strong evidence that Saint Theosevia the Deaconess was the wife of Saint Gregory of Nyssa, but this is not generally accepted for lack of complete evidence. An ambiguous expression in the Letter of Condolence written by Gregory the Theologian to Gregory of Nyssa upon the death of Theosevia the Deaconess, expressly calls her his "sister" and "consort". The latter word "consort" in Greek is syzigon, which also means "spouse". This and other language certainly indicates a close relationship which scholars generally agree either mean she was Gregory of Nyssa's wife or sister.
It should be mentioned also that in his treatise On Virginity (ch.3), Gregory of Nyssa does indicate that he may have been married, though this also is a bit ambiguous.
Below is Epistle 197 of St. Gregory the Theologian to St. Gregory of Nyssa in honor of St. Theosevia upon her repose:
I had started in all haste to go to you, and had got as far as Euphemias, when I was delayed by the festival which you are celebrating in honor of the Holy Martyrs; partly because I could not take part in it, owing to my bad health, partly because my coming at so unsuitable a time might be inconvenient to you. I had started partly for the sake of seeing you after so long, and partly that I might admire your patience and philosophy (for I had heard of it) at the departure of your holy and blessed sister, as a good and perfect man, a minister of God, who knows better than any the things both of God and man; and who regards as a very light thing that which to others would be most heavy, namely to have lived with such a soul, and to send her away and store her up in the safe garners, like a shock of the threshing floor gathered in due season, (Job 5:26) to use the words of Holy Scripture; and that in such time that she, having tasted the joys of life, escaped its sorrows through the shortness of her life; and before she had to wear mourning for you, was honored by you with that fair funeral honor which is due to such as she. I too, believe me, long to depart, if not as you do, which were much to say, yet only less than you. But what must we feel in presence of a long prevailing law of God which has now taken my Theosebia (for I call her mine because she lived a godly life; for spiritual kindred is better than bodily), Theosebia, the glory of the church, the adornment of Christ, the helper of our generation, the hope of woman; Theosebia, the most beautiful and glorious among all the beauty of the Brethren; Theosebia, truly sacred, truly consort of a priest, and of equal honor and worthy of the Great Sacraments, Theosebia, whom all future time shall receive, resting on immortal pillars, that is, on the souls of all who have known her now, and of all who shall be hereafter. And do not wonder that I often invoke her name. For I rejoice even in the remembrance of the blessed one. Let this, a great deal in few words, be her epitaph from me, and my word of condolence for you, though you yourself are quite able to console others in this way through your philosophy in all things. Our meeting (which I greatly long for) is prevented by the reason I mentioned. But we pray with one another as long as we are in the world, until the common end, to which we are drawing near, overtake us. Wherefore we must bear all things, since we shall not for long have either to rejoice or to suffer.
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It should be mentioned also that in his treatise On Virginity (ch.3), Gregory of Nyssa does indicate that he may have been married, though this also is a bit ambiguous.
Below is Epistle 197 of St. Gregory the Theologian to St. Gregory of Nyssa in honor of St. Theosevia upon her repose:
I had started in all haste to go to you, and had got as far as Euphemias, when I was delayed by the festival which you are celebrating in honor of the Holy Martyrs; partly because I could not take part in it, owing to my bad health, partly because my coming at so unsuitable a time might be inconvenient to you. I had started partly for the sake of seeing you after so long, and partly that I might admire your patience and philosophy (for I had heard of it) at the departure of your holy and blessed sister, as a good and perfect man, a minister of God, who knows better than any the things both of God and man; and who regards as a very light thing that which to others would be most heavy, namely to have lived with such a soul, and to send her away and store her up in the safe garners, like a shock of the threshing floor gathered in due season, (Job 5:26) to use the words of Holy Scripture; and that in such time that she, having tasted the joys of life, escaped its sorrows through the shortness of her life; and before she had to wear mourning for you, was honored by you with that fair funeral honor which is due to such as she. I too, believe me, long to depart, if not as you do, which were much to say, yet only less than you. But what must we feel in presence of a long prevailing law of God which has now taken my Theosebia (for I call her mine because she lived a godly life; for spiritual kindred is better than bodily), Theosebia, the glory of the church, the adornment of Christ, the helper of our generation, the hope of woman; Theosebia, the most beautiful and glorious among all the beauty of the Brethren; Theosebia, truly sacred, truly consort of a priest, and of equal honor and worthy of the Great Sacraments, Theosebia, whom all future time shall receive, resting on immortal pillars, that is, on the souls of all who have known her now, and of all who shall be hereafter. And do not wonder that I often invoke her name. For I rejoice even in the remembrance of the blessed one. Let this, a great deal in few words, be her epitaph from me, and my word of condolence for you, though you yourself are quite able to console others in this way through your philosophy in all things. Our meeting (which I greatly long for) is prevented by the reason I mentioned. But we pray with one another as long as we are in the world, until the common end, to which we are drawing near, overtake us. Wherefore we must bear all things, since we shall not for long have either to rejoice or to suffer.
Source