"Supergirl is what I can do, Kara is who I am", this quote is a reference to "Lois and Clark: The New Adventures Of Superman" (1993), Tempus Fugitive (1995): Clark: Lois, Superman is what I can do. Clark is who I am.
Kevin Sorbo is known for playing the main characters in two other popular science fiction series. He portrayed Hercules in Hercules: The Legendary Journeys (1995) and Captain Dylan Hunt in Gene Roddenberry's Andromeda (2000).
Lillian quotes Friedrich Nietzsche's philosophy "Towards the Ubermensch" to Jeremiah that he should be her Superman. Dean Cain played Superman in Lois & Clark: The New Adventures of Superman (1993).
First appearance of Teri Hatcher on Supergirl.
In the comics, Mon-El's real name is Lar Gand the same name as Kevin Sorbo's character. Mon-El first appeared in Superboy #89 (first series). Mon-El was rocketed to Earth, Superboy thought that it was his brother since there was a letter from his Kryptonian father, Jor-El. Superboy found him on a Monday and since El is the last name of Superboy (Kal-El) thus finding him the name Mon-El.