If it was real, Flynn and Alice would have been married long ago and at least a couple of kids by now. Single people in the village wouldn't have stayed single this long.
People did generally get married earlier, but at the same time it wasn't that uncommon for people to get married for the first time later like in their 20s. Main reason why people got married early was because of convivence but nether Flynn or Alice really wanted to stay in the village anyway so there isn't much reason to get married. It would actually make moving and studying in the capital more difficult. The idea of everyone getting married at like 16 isn't really that accurate. Men at least were typically a older when they got married than women, because they would spend the first few years of their adulthood trying to establish themselves. Women were only married earlier because they weren't expected to do much besides support their husbands