That stuck out to me because it’s absolutely untrue. Deitsch/Pennsylvania Dutch has “liiwe/liwe/liewe” (there is no standard written orthography for the language) which is precisely “lieben” in standard German. The author absolutely knows this despite her implicit claim that it’s a loanword rather than part of the vocabulary (which it absolutely is, even if her community is sparing in how they use it in Deitsch).

It’s certainly true that Amish much less the small and peculiar Libby community (which isn’t representative of wider Amish culture although part of it) have different ways of expressing feelings just as Germans are different from Americans and have very different ways of relating.

Bear in mind that she went from a remote group of emergent Amish to UC Berkeley, she is a fairly young writer and obviously still processing her background.