This activity is a worksheet that students can do individually or with partners. It can be done as an introduction to the vocabulary, but I like to make it a fun race after we have already practiced the vocabulary more and have discussed "el __ de ___" possession construction in more detail. To race, I have students work in pairs to try to be first to complete the chart correctly.
In whichever way you choose to have your students complete the worksheet, have them ill in the first blank under each family member. Following the examples, they must then fill in the second blank that is under only some of the family members with another way to describe the family member. For example: el hermano, el hijo de mi padre.