family relationship vs kinship

family relationship and kinship both are nouns.

Word	Noun	Adjective	Verb	Adverb
family relationship	Yes	No	No	No
kinship	Yes	No	No	No

As nouns, family relationship and kinship are synonyms defined as:

family relationship and kinship: (anthropology) relatedness or connection by blood or marriage or adoption

Other synonyms of family relationship include relationship.

family relationship (noun)	kinship (noun)
(anthropology) relatedness or connection by blood or marriage or adoption	(anthropology) relatedness or connection by blood or marriage or adoption
	a close connection marked by community of interests or similarity in nature or character