Bart is Herb's...
Nephew
Mona is Bart's...
Grandmother/Grandma
Lisa is Mona's...
Granddaughter
Abe and Mona are Lisa's...
Grandparents
Lisa is Maggie's...
Sister
Marge is Homer's...
Wife
Bart is Maggie's...
Brother
Bart is Jacqueline's...
Grandson
Bart, Lisa and Maggie are Ling's
Cousins
Bart, Lisa and Maggie are Clancy's...
Grandchildren
Homer and Marge are Bart's...
Parents
Lisa and Maggie are Herb's...
Nieces
Herb is Bart's...
Uncle
Bart, Lisa and Maggie are Marge's...
Children/Kids
Homer is Marge's...
Husband
Selma and Patty are Lisa's...
Aunts
Maggie is Homer's...
Daughter
Ling is Patty's...
Niece
Bart is Homer's...
Son
Abe is Bart's...
Grandfather/Grandpa