Chacha's already answered this one as well as I can! Some Lalafellin families (we've only seen royal families) use a single-syllable "middle" name to denote family like Ul or Sil.
The example of the Coco brothers all sharing the same AA repeated-syllable opener can denote family ties, however, it's not the only way to do so and another instance of a family-set of Dunesfolk Lalafells have something as simple as having "kk" in each of the C-syllabic suffixes of their forenames:
Seserukka, Popokkuli, and Nenekko.
Shalala and Checheroya, the mother and father of the above three siblings do not share the double 'k' as you can see. So it appears to be entirely up to the parents to come up with a common naming theme/component for their children.
The example of the Coco brothers all sharing the same AA repeated-syllable opener can denote family ties, however, it's not the only way to do so and another instance of a family-set of Dunesfolk Lalafells have something as simple as having "kk" in each of the C-syllabic suffixes of their forenames:
Seserukka, Popokkuli, and Nenekko.
Shalala and Checheroya, the mother and father of the above three siblings do not share the double 'k' as you can see. So it appears to be entirely up to the parents to come up with a common naming theme/component for their children.
