Here is a great rubric for a Family Tree Project. It is easy for both the teacher and student to understand. Once you have passed this out to each student have them staple it to their project when they turn it in. Makes grading easy-peasy!
A second page is included for working on their draft sentences. A great way to work together as a class and prepare. Some students may need the extra structure as a requirement while other students may be encouraged to venture "Above and Beyond" these sentence starters.
And if using their own family is too stressful...have them invent a family, use a TV family, or describe a friend's family.
AND if you have all your students make these on apple/fruit/FUN shaped papers you can make a class-tree bulletin board out of all the projects!