It did not take him long to give me children. Two sons in three years. Three good years. (1.1.15)
Anna and Sam's relationship might not be one of the great romances of their time, but the two enjoyed a happy life together. In particular, Anna was fulfilled in her role as a mother.
God [...] sets in a mother's heart such a fierce passion for her babies that I do not comprehend how He can test us so. (2.2.37)
In Anna's day, infant mortality rates were insanely high, even without taking the plague into account. It was a rough era. Although losing a child would be painful for anyone, it hits Anna particularly hard because she's such a strong maternal figure.
George Viccars brought laughter back into the house. (2.2.5)
George Viccars isn't just some eligible hunk to Anna—he's her best hope for a new father figure for her sons. She wants to feel like she has a real family again.
She regarded me gravely. "Your arms will not be empty forever. Remember that when the way looks bleak to you." (2.5.8)
Here are some prescient words, courtesy of Anys. While we doubt that she can actually see into the future (that would be pretty sweet, though), Anys rightfully supports her friend in her time of need. She knows how important family is to Anna.
I knew I would have to [...] return to my own cottage, silent and empty, where the only sound [...] would be the phantom echoes of my own boys' infant cries. (2.7.57)
After successfully delivering the Danielses' baby boy, Anna is struck once again by grief over the death of her children. On one level, it's comforting to see such a happy family and reconnect with her maternal side, but the experience also reminds Anna of everything she's lost. It'll take some time for that ache to go away.
Perhaps, if my children yet lived, [...] I would have been driven to consider a desperate flight. (2.7.27)
Here, Anna wonders if she would have left Eyam if she still had her children to worry about. Ultimately, she realizes that she probably would have stayed put regardless, if only because her family wasn't wealthy enough to afford an abrupt uprooting.
I believed that Aphra would do it. [...] For whatever I felt toward him, I would not have left my father to die in such a way. (2.11.73)
Although Anna has a pretty awful relationship with her father, she would never have abandoned him if she had known that Aphra wasn't coming to the rescue. That's a testament to her character. Despite the pain her father has caused her, she still has empathy for him.
I was finally able to fashion a scale on which I could weigh my father's nature and find a balance between my disgust for him and an understanding of him. (2.12.4)
Anna makes peace with her father's memory by thinking about the life circumstances that shaped him, for better or for worse. Mostly for worse. As a boy, Josiah Bont experienced a great deal of abuse and trauma, causing him pain that he later took out on innocent people like Anna. That doesn't excuse his actions, but it does help us understand them.
"You think I can't see through you? You're not my stepdaughter now. Oh, no. You're too fine for the like o' me. You're her creature." (2.13.73)
Despite Anna's soul-searching, Aphra is never able to forgive her. Interestingly, this passage suggests that she's angry with Anna because she chose a different family—the Mompellions—over her own. Does that idea change your perception of Aphra?
Aisha grabs one hand. Elinor clasps the other, and together we plunge into the jostling swarm of our city. (e.23)
In the end, Anna builds herself a new family. This new family might have been formed out of tragic circumstances, and it might be living in a wildly unfamiliar land, but Anna Frith wouldn't have it any other way.