blood is thicker than water
The proverb that family ties outweigh other ties.
The saying means kinship binds more tightly than other relationships. It is a cliché. If you use it, mean that. Do not dress it up as fresh wisdom. If you need the thought, a plain sentence will do: Family won out.
Examples
UseFamily won out.
AvoidBlood is thicker than water, after all, when the will was read.