Symbolism, Imagery, Allegory
Don't worry—these aren't the creepy, horror movie kind of dolls. But, in a way, the manner in which doll imagery is used in Our Mutual Friend is even spookier.
There's a ton of manipulation going on in this novel: people take turns playing the "puppet master" and playing with other characters' lives as if the characters themselves were nothing more than inanimate objects. Villains like Fledgeby constantly use the people around them (like Mr. Riah, for example) to play out their dastardly schemes.
But there's another spooky layer to the doll symbolism in this novel. We're talking about Jenny Wren: not only does she earn her living making clothing for dolls, but she has to take care of her father. And what toys do children use when they're playacting care-giving? Bingo: they play with dolls.
Jenny is neglected; her father is a falling-down drunk who not only cannot care for her, but also needs to be "parented" by his own daughter. Sad stuff. But Jenny's no slouch; she's a strong, resourceful girl who copes with having to act wise beyond her years by thinking of her dad as a doll. She even calls him "Mr. Dolls."
A byproduct of Jenny's unfortunate (and confusing) role as mother to her own father is that she starts to refer to actual dolls in human terms. Maybe it's because the roles of caretaker and cared-for are all messed up in her head, or maybe it's because she's isolated, but she says things like:
And I made her try on—oh! and take pains about it too—before she got seated. That's Lady Belinda hanging up by the waist, much too near the gaslight for a wax one, with her toes turned in. (11.2.35)
Cue the ominous string music. But don't worry too much about Jenny. She—like all the awesome characters in this novel—meets with a happy ending.
Her tendency to treat humans like dolls and inanimate dolls like humans mirrors of a lot of characters' attitudes in this book: they have a tendency to distance themselves from human interaction, and to find comfort in objects. But hey—if you had to deal with the Weggs, Fledgebys, and Mr. Dolls of the world, wouldn't you rather hang out with things than people?