Age
We don’t get many clues as to how old Caroline is. She does seem to boss her brother around, which would imply that they’re of a similar age, but if she were the age he likely is (mid-to-late 20’s), she’d be considered a bit of an old maid.
Family and Situation
Caroline is the sister of Charles Bingley and Louisa Hurst. Though she’s keeping house for her brother, it would seem that she’s actually closer to her sister Louisa; we know that Caroline spends three weeks in Scarborough with the Hursts in September towards the end of the book and Caroline and Louisa are forever being nasty together. Of course, on the other side, Caroline’s note inviting Jane to Netherfield seems to imply that if she and Louisa are left to their own devices for a whole day they cannot help but quarrel.
We also know that her father made a fortune in trade and that the family comes from “the North of England.” She carries a dowry of £20,000, and had been educated “at the finest seminaries in town”, suggesting that however the fortune came about, Caroline grew up with money. At the beginning of the novel, she is serving as housekeeper for her brother at Netherfield Park, which he is renting.
Other Connections
Caroline is, throughout the novel, eager to build relationships with persons of high rank. She claims great acquaintance with the Darcys, but begins teasing Mr. Darcy considerably more once she realizes that Elizabeth Bennet has caught his attention and is downright awful to Lizzy after that point. Col. Fitzwilliam admits to knowing Bingley’s sisters “a little” and Caroline professes great intimacy with Georgiana, though given her mis-steps at Pemberley, it’s unclear how accurate this portrayal actually is. We do know that she’s “mortified” by Darcy’s marriage but still spending time with Georgiana, suggesting that it is prestige, and not the man himself, with whom she is infatuated.
Appearance
The general opinion at the Meryton Assembly is that Caroline and her sister are “fine women, with an air of decided fashion,” which seems to imply they’re well turned-out but somewhat pompous.
Character
Caroline and her sister are often described jointly. Early on, the narrator tell us that “They were in fact very fine ladies; not deficient in good humour when they were pleased, nor in the power of making themselves agreeable when they chose it, but proud and conceited. They were rather handsome, had been educated in one of the first private seminaries in town, had a fortune of twenty thousand pounds, were in the habit of spending more than they ought, and of associating with people of rank, and were therefore in every respect entitled to think well of themselves, and meanly of others. They were of a respectable family in the north of England; a circumstance more deeply impressed on their memories than that their brother's fortune and their own had been acquired by trade.”
We're told that when Elizabeth and Jane spend time with Bingley’s sisters while at Netherfield, they’re surprised to learn that “They could describe an entertainment with accuracy, relate an anecdote with humour, and laugh at their acquaintance with spirit,” suggesting that it’s either men or persons of power more generally who make them awful.
Habits and Hobbies
Caroline has many opinions about who qualifies as an accomplished woman, presumably because she considers herself accomplished. We know that she can play the pianoforte and that she was “educated at the finest seminaries in town”, so it’s likely that she speaks a number of languages and has many of the standard female “accomplishments.” Coupled with her significant inheritance, one would think this makes her highly eligible marriage material.
