I'm not sure because I've never read the poem before, but just some tips:
1. think about why the author wrote this poem
2. What do you think about it
3. Read it over and over until you can understand what the author is saying perfectly
4. Ask an adult to help you understand the poem if you're having trouble
Donc ils s’amusent ( normalement)
Bart est le frère de Lisa.
Homer est le père de Lisa.
Patty est la tante de Lisa.
Marge est la mère de Maggie.
Abe est le grand-père de Bart.