One of the best ways to help students make meaning of vocabulary and retain what they learn is to categorize a list of vocabulary and think through the meanings of each word/phrase. Regardless of your choice of family vocab words and phrases, it's easy to use this sheet to help students make these choices while still staying immersed in the target language.
Personally, I have students who come from diverse backgrounds so I give many different family members in our vocab to help students feel more comfortable. I chunk the activity into three portions, and I walk them through the meta-cognitive process of making the first classification or two in the target language (quel est l'âge typique, à propos de vous (par exemple, les cousins à vos âges sont typiquement les enfants ou les ados; c'est un garçon ou une fille; typiquement, dans une famille "normale", qui habite dans une habitation- making sure here to take a moment to explain in English that you are including step/half family members but not grandparents/aunts/uncles/etc., even though these are completely normal and awesome families, we are classifying based on a semi-nuclear model of family).
I use this activity with French 1 and I've used it as early as the 2nd quarter with mostly target language and very few problems in comprehension/responses. The retention of this vocabulary has been greatly enhanced by this activity, and I've been adjusting other units to include this skill as I continue my journey towards more and more CI-based practices in the classroom.