Will Isabel ever find Ruth?

The answer to this question is going to change depending on each reader's opinion of Isabel and the ending of Chains.  Throughout the novel, Isabel works extremely hard to make sure that she and Ruth stay together.  Isabel is even willing to take a beating for Ruth, so readers are likely to believe that Isabel will do anything in her power to stay close to Ruth.  Unfortunately, Isabel and Ruth are slaves.  Their fate is subject to the will of their owners, and Madam Lockton is not a kind and loving owner.  She is every bit as violent and conniving as her husband.  In an effort to hurt Isabel, Madam Lockton gets rid of Ruth. She tells Isabel that she sold Ruth.  In chapter 43, readers discover that Madam Lockton did not actually sell Ruth.  She could not find a buyer, so Madam Lockton sent Ruth to her property in Charleston. 

"Brat," Madam spat. "Couldn't find a buyer. Had to ship her down to Charleston. I shall tell the estate manager to get rid of her, toss her in the swamp. Her death will be on your head, you insolent fool."

At this point, Isabel is supremely motivated to escape the Lockton household.  She successfully does this, rescues Curzon, and escapes the city.  That is when the novel ends.  The exact fate of both Isabel and Ruth is left completely open. I do think, however, that the story ends in a way that is meant to suggest that Isabel will track down and free Ruth.  Based on her tenacity, intelligence, and strength of will demonstrated throughout the story, I do believe that Isabel will fight "like a lion" and find Ruth.