She's in 1750s London to make sure the murder of Benjamin Franklin is averted.  His murder was the first in the string of events orchestrated by Westchester to convolute the timeline.

"She had lain awake for hours rehearsing her method of interrogation. She wasn't quite sure what approach to take. Maybe the 'indignant about the intrusion' approach or 'scared about the intruder' approach or the 'wasn't it so exciting' approach but none of them seemed right. She wanted to use the 'I was dressed up as a boy last night because I'm a time traveler from an alternate history and I'm trying to make everything right again' approach, but knew that was a nonstarter."

So we have this selfish, narcissistic and aristocratic Englishman, Westchester, who wants to get back the lands and title that once belonged to his family, but were lost in the eighteenth century.  His associate has discovered how to time travel and they go back to make enough changes to satisfy Westchester.  (We have no idea, yet, why Odell agreed to this.  And, actually this is an assumption on my part, because the story starts right in with the changed timeline.)

now that they've come back to contemporary times, all has changed and not in a good way.

we are following the story from The viewpoint of Odell's sister, Odette.  It's interesting because she has no idea of what the changes have wrought. From her perspective, this has always been the way life is.  Her brother is horrified at what he has done.  

This is is the world they live in:  

"New York City, 2028

Odette stepped off the curb only to jump back again and curse under her breath. The speeding hansom cab hit a pothole and sprayed her with last night's rain. It splattered her knee–high boots with mud and left the hem of her woolen cloak dripping.  She glanced up at the heavily painted face in the carriage window – all rouge and false eyelashes. The aristocrat looked with distaste at Odette's immodest garb and turned away, her long, straight nose held at a disdainful angle. 'Boiler hag!' Odette yelled after the cab, making sure no one was around to actually hear her. . . 

 . .  Odette felt the heat of anger steal over her. As a commoner, she might rise to the level of comfort, even wealth.  However, the portals of power and high society would always be closed to her. She would always be . . . inferior. . . . After the cake incident [she publicly refused the advances of Lord Westchester by smushing a piece of cake in his face at a reception], her career was left in tatters. No one would dream of hiring her so she had to turn to the only available alternative, working as a dancer in clubs and taverns.

Damn Lord Westchester and all those like him! Is this how she survived, avoiding men, hiding her femininity? A prisoner to others' desires?

[Two hundred years ago, a Code was passed into law.]  'The code's stupid.' Odette snorted in disgust. 'It's indecent for me to wear pants, but my breasts can hang out of a low-cut dress. I can't uncover my legs, but some skirts are so sheer they're transparent. I can show as much skin as I like dancing on the stage but not walking down the street. It's indecent for you to own a business but not to work for a man. . . . The bloody code is indecent.'

. . . skirts were almost transparent and made of fabric that clung and left little to the imagination. But the legs were always covered or hampered in someway. Odell understood this fixation with women's legs. It was a cheat. Modesty had nothing to do with it, not if the prevailing fashion was any indication. Restricting freedom of movement was it's only purpose."

I'm at 10%,  and looking forward to finding out the answers to the questions:

what the world was like before the change.

How Odell discovered the means for time travel.

how did Westchester orchestrate the changes, and how did he come to be so dastardly --he likes the world he lives in now, but wants to tweak it a bit.  (Mercedes Benzes are ever so much more luxurious than steam powered hansom cabs.). But the class system, as far as he is concerned, is fine the way it is, and he doesn't care to change that one bit.  "There was an enormous population of peasants and commoners to bow and grovel and scrape, most living in abject squalor. The smell was appalling. He had believed that advances in robotics and farming would have eliminated the need for most of them, leaving just a small clean servitor class of technicians and artificers, artists and sexual playthings. He hadn't thought things through clearly enough, but he could use that machine of Odell's to make everything come out right.  Just some little changes here and there." His goal is to ensnare Odette, and use her to continue to control Odell.

I'm expecting that Odell is somehow going to break free of the evil influence of Westchester, and go back and fix this.  He's going to have some problems though. "They would never allow technology to develop in any democratic sense, to be used for the greater good. True innovation required an open society and that was one thing they would never tolerate."

Odell has just invited Odette to dinner for The Big Reveal.

On with the story.  I'll keep you posted.