Cousinliness

Unkindness would have implied intimacy, or, at any rate, cousinliness, whereas, but for his presence in her boudoir, and his familiar tone with her mother, a stranger might have supposed the two young people to be the merest casual acquaintances.

Source: wiktionary

Now perhaps you will understand why, feeling this exuberance of joy and loving kindness as I mostly do, and your defenceless head having popped up within my range of late, I shower so much affection on you—quite passing the mild limits of cousinliness.

Source: wiktionary

There was no way that Elizabeth, with her own particular nature, could have indulged in feelings of sisterliness or cousinliness towards Mary, as she had to defend herself: it was ultimately survival.

Source: wiktionary