Fridge Brilliance At the end it shows Darla working as a janitor, still as a child. Lax child labor laws, or is Darla ?
Really 700 Years Old In the last song, "Nothing's Gonna Stop Us Now," Darla inadvertently makes their performance big AND loud—exactly what she was preaching to Danny a few scenes ago.
Fridge Horror Where exactly are Darla's parents?
Darla could probably be an orphan.
Or, as the above mentioned, she could really be older than what she looked and isn't living with her parents
Alternatively, Max could be her guardian hired by her parents, or (a la Sunset Boulevard) he's actually her father.
She fired them.
As pointed out on the YMMV page, the flood Darla caused could have injured or killed several people, not to mention the damage costs to the studio.
Maybe that's how she lost her money as well as her career. Perhaps she was forced to pay for the damage?
Before the ivory trade was banned, piano keys were made from elephant ivory. When Wooly plays the piano, he's pressing keys made from dead elephant tusks.
Fridge Logic Why didn't Mammoth just film Wooly once for their Vanity Plate?