the "hooker with a heart of gold is an old trope.... so i can see where you might not look beyond that.

but I think.Thematically she represents true love.

The movie is all about undermining the perceptions. the rich are vain and greedy and cruel untrusting and untrustworthy. Penelope without even bothering to listen to the man "she loves" just condemns him and casts him aside.

In a world full of people who are shallow, fakes, liars, and cruel, despite the wealth and power to do good. It is Ophelia, at the very bottom of the society, who is the best, most altruistic character.

She is the only one who never betrays her ideologies, never takes advantage, never hurts anyone, she only helps and supports and and heals.

when we meet her Ophelia is hiding her true self behind her wigs and fake voice, playing a joke she thinks. but when she sees the real harm she caused she can't just walk away. she HELPS.

at first she is distant and cold and seems to want to keep her costume and her adopted "hooker" persona. a cash transaction. But why? because she is "responsible" for some of Louis' plight and she can't just walk away....as she learns Louis' story she opens up more and more...and when she takes her disguises off, along with her bra ironically, she begins to show her true self as a smart capable women with a plan. and even begins to be vulnerable.

then they grow and become friends and ultimately they fall in love. truelove that isn't hindered by her status or her past or the class divide between them...in the end after all the hijinks and gaffs and jokes and the revenge they take......she is the love of Louis' life. and they "live happily ever after" on the giant pile of money they made.