Kanhlengi prefer large age gaps in relationships, so much so that they have separate words for "older spouse" and "younger spouse" (both derived from "sitë") instead of native words for "husband" and "wife". They typically marry at least twice in their lifetime, once in youth to someone old, and then after getting widowed, once in old age to someone young.
Traditionally, the younger spouse takes the family name of the older spouse, regardless of gender. The younger spouse also typically moves into the older spouse's house and helps to parent any children from previous marriages. This dynamic creates a "marriage line" across the spousal generations, which has influenced kinship terms in Kanhlengo.
For instance, there are terms that roughly translate to "grandspouse", "great-grandspouse", etc., which refer to your older spouse's older spouse and so on. There are also terms for your younger spouse's younger spouse, but these often only appear in legal documents such as wills, as you normally die before your spouse remarries.
Since the children of your spouse and grandspouse tend to be close in age to you, they are referred to as "siblings" instead of "step-children". The Kanhlengo term for "sibling" means more "member of the same house near the same age, regardless of actual biological relationship". In fact, when two people with a small age gap marry, they are derisively referred to as "siblings", as marrying someone close in age is seen as taboo.
This "sibling" logic extends even further. So you are an "uncle/aunt" not only to your biological siblings' children, but also to the children of your older spouse's children. Also, you are a "cousin" to your parent's older spouse's grandchildren. As a result, kinship terms are highly complex in Kanhlengo, but seeing as it is taboo akin to incest to marry someone in your older spouse's family, it makes sense for Kanhlengi to keep track.