I was able to find the complete instructions for the exercise online.
Here, you have to write in Isabel's family tree every relationship under the picture of the person in Spanish.
In this case, the two people that appear on top are abuelo and abuela.
Then, you follow the arrows and you have madre and tío. Next to madre, you have padre, and next to tío, you have tía.
Finally, in the last line of the family tree, there is Isabel's sister next to her, so you write hermana; and below tío and tía, you have Isabel's cousin, so you write primo.
Here you have the picture to see the complete family tree.