Hey Bettina, maybe "sororidad"? it is a really nice word in Spanish it means sister love, and also It is used to refer to the solidarity between women. It is a word that comes from Latin.

Hello Bettina, if you feel your family is the most important thing you have, creo que FAMILIA is a very meaning word. I know is similar than in English, but for Latin people Family is an strong word. Maybe you can use a phase: Lo primero es la familia

Probably better than a word, what defines more Spain and Spanish is the letter "ñ", or in capital letters "Ñ". BTW, I do not like tattoos, but you can do whatever you want.