Not sure if this distinction made it through the ensuing discussion: a marriage may be valid but not sacramental. Or, to put it another way, not all valid marriages are sacramental.
For example, my marriage to my Quaker wife was valid but not sacramental because my wife was not baptized. We had to obtain a dispensation for “disparity of cult.” When my wife came into full communion with the Church, not only did she receive Baptism, Confirmation, and Eucharist in one ceremony, we both received Matrimony as well. When the conditions for sacramental marriage occurred, our marriage became sacramental.
I love the sacramental economy.
JSA