Non-Christians Have Valid, Non-Sacramental Marriages
How can one be married "non-sacramentally''? I have never heard of this.
A valid sacramental marriage is between two Christians. Yet, as Jesus himself acknowledges, valid marriages between non-Christians existed (see Gen. 2:23-24) long before he elevated marriage to the level of a sacrament (Matt. 19:1-9, Eph. 5:21-33).
Indeed, marriage was a natural institution long before Jesus raised it to the level of a sacrament. Consequently, the Church recognizes as valid—until otherwise proven—the marriages between non-Christians. More could be said about the distinctions between natural and sacramental marriages, but I recommend for now examining the Catechism of the Catholic Church’s treatment of this important topic (CCC 1601ff.)