WMG / Candy♡Candy

Manga

Candy is a Cornwell

We are never told any clues about who Candy's true parents are, but there is a possibility she is one of the long lost daughters of the Cornwells (or at least distantly related to them).

Candy White and Anthony Brown both have blonde hair and green eyes. Similarly, Candy is the only one of the Audreys who's a nice, down-to-earth person unlike Neil and Eliza, whereas Anthony is the nicer one between his brothers.

The unknown man at the end was Terry

In the Grand Finale, it's shown Candy finally ended up with someone, though we don't know who. Given how Archie is with Annie, Anthony is deceased, and Stear died in World War I, this leaves Terry as the only viable candidate for her. William/Albert/The Prince on the Hill is certainly an option, but he's also technically related to Candy^note then again, this doesn't seem to be an issue for the Leagans, since Neil also wanted to marry Candy despite being her adoptive brother. Candy and Terry split on amicable terms and he left to pursue his career, so it's likely that now they're adults, they're finally together again.

• This analysis also seems to believe it was Terry.

The Leagans are a mafia family

The Leagans are stated to be one of the most influential families in all of America. This is a huge claim to make, considering that the US is one of the largest countries in the world (even during the 1920s, when this anime is set) and is already home to several other influential families from all over the world.

The head of the Leagans, William, refuses to show himself in public, communicates through telegrams and letters and is so isolated that even most of his family members only have an arm's length view of him. This is similar to how many Real Life mafia bosses operate - they're up against the police and rival mafias, after all. William likely does this to that his family is safe from their wrath, and while also sharing with them the immense profits of his mafia business.

Him (or his ancestors) are possibly seasoned mafia members, and also why Elroy is so authoritarian - she is the mother of their (potential) successors after all. The main reason Eliza acts so cruel and belligerent is because she's training to be next in line, and her cruelty to Candy is her going on a power trip. This is also reflected in Eliza's Rich Bitch attitude.

• Somewhat Jossed as it's revealed that he's Albert, aka The Prince on the Hill, using a persona.

Eliza has incestous feelings for Neil Leagan

Eliza has feelings for Neil and the main reason she hates Candy is jealousy.

The Leagans establish that they don't have an issue with incest when in the final arc, Neil tries to marry Candy, and Elroy supports him. This is despite the fact that many times, Candy has been referred to as his and Eliza's adoptive sister. The marriage attempt ultimately falls through since Candy doesn't reciprocate.

Eliza, despite being a horrid Alpha Bitch who's harsh to even her own best friend Louisa, cares for Neil greatly to the point she's distressed when he's hurt. She is a cruel person to the core, yet Neil is the only person she's ever shown kindness to. However, Eliza is also crude and overbearing, and this is why Neil could never love her back.

Neil, who had always been used to a life of emotional abuse from Eliza, [[spoiler: fell in love with Candy because of her gentle nature. It's possible that even before Candy beat up the thugs harassing him, he had feelings for her since he wasn't mean to her unless Eliza constantly pressured him. Eliza must have caught on, and this caused her burning hatred for Candy, as Candy has now taken Neil from her on top of Anthony and Terry.

• The Leagans likely didn't see her and Neil's union as incestous because she's adopted.

Crossover

The Brightons are related to the Brightons

• In support of this theory:
  • The Brightons in Lady are a wealthy family from England, the Brightons in Candy Candy are a wealthy family from America.
  • According to the Lady sequel manga, the Brightons have family in America (specifically Barbara).
  • Both the English and American Brightons have blonde hair. Annie is also mentioned to look like the Brighton's deceased child, and her manga incarnation can pass for Arthur's sister with her hair and eyes.
  • Annie attends St. Paul's school in London, and the Lady Brightons live in London.
  • Word of God is that Candy♡Candy inspired Lady.
• Against this theory:
  • The Brighton family have black hair in the anime.
    • Only the father. The mother is a blonde.