Amish typically marry in their early 20s, after the adolescent period Rumspringa
If an Amish person falls in love with an outsider, a rare occurrence but one not unheard of, the couple face a dilemma. The Amish-raised individual must either opt out of Amish baptism, or, typically the harder choice, the non-Amish person may consider joining the Amish church.
Amish typically see joining purely for love as not the best reason, though it does happen. One Amish bishop quoted in Richard Stevick’s Growing Up Amish explained that “When seekers from the outside come to us wanting to be Amish…they are often attracted for the wrong reasons. They could have fallen in love with one of our Youngie. Or they may have fallen in love with what they think is a simpler way of life. What they fail to realize is that our faith in Christ is at the center. Horses, buggies, and kerosene lanterns will quickly grow stale without the faith foundation.” (Growing Up Amish, Stevick, p38).
Amish may remarry
Amish divorces are extremely rare. An Amish couple may separate, but divorce is nearly unheard of. One Amishman estimated that there are perhaps a half-dozen separated couples in the large Holmes County, Ohio community. Remarriage after one partner has died is permitted among Amish, however, and occurs fairly frequently, even among Amish of advanced age.
For further information, see:
Growing Up Amish: The Teenage Years, Richard Stevick
Amish Society, John A. Hostetler
New York Amish: Life in the Plain Communities of the Empire State, Karen Johnson-Weiner