Rebecka, youngest sister of Felix, who married the distinguished mathematician Peter Gustav Lejeune Dirichlet.
Paul, brother of Felix, he became a banker.
Abraham, son of the philosopher Moses Menedelssohn, and the father of Felix; Hensel married Fanny, Felix's sister, who was also musically gifted. Abraham changed the family name to Mendelssohn Bartholdy, in connection with their conversion to Christianity, but we don't bother with that in the English-speaking world!
Fanny as a young girl.