"Is this aunt as peculiar as all the others?" was all she said. Mo had already taken her to visit various relations. Both he and Meggie's mother had large families whose homes, so far as Meggie could see, were scattered over half of Europe. (2.12)
The way Meggie thinks about her extended family, it's almost as though they've been scattered like dandelion puffs by the wind across a whole continent. This could either mean that they're adventurous folks who like living in different places, or that they don't play nice with others (once we meet Elinor, we tend toward the latter explanation). Still though, family is family, and you gotta be nice and visit them from time to time.
"I'd do anything for a good bookbinder, and anyway you're my niece's husband. I really do miss her sometimes, you know. I expect you feel the same. Your daughter seems to be getting along all right without her, though." (5.6)
Oh, Elinor, you're so blunt. Of course she's willing to help out Mo, because he's such a fabulous bookbinder… oh, right, and they're related by marriage too. Mustn't forget that last bit. Elinor also puts her foot in her mouth and says that Meggie seems to be doing fine without her mom—though Mo, obviously, is not doing so great without his wife, but that doesn't seem to occur to Elinor.
"Pigheaded, isn't she?" remarked Elinor. "It almost makes me like her! Her mother was just the same, I remember." (5.13)
Like mother, like daughter… or so Elinor seems to think. Stubbornness does indeed seem like something one can inherit from a parent. Meggie wouldn't know, of course, since her mom vanished when she was three years old, back before she was able to remember very much of her.
"Ah, well, you'll probably never be as crazy as I am! […] Your father's not inclined to be crazy, and your mother never was either. Quite the opposite—I never knew anyone with a cooler head. My father, on the other hand, was at least as mad as me." (6.31)
Elinor characterizes her family as crazy, and not necessarily in a good way. That gene seems to have skipped Meggie's mom, though, and Meggie's dad seems sane in Elinor's eyes, too. Possibly this is because he hasn't yet revealed that he accidentally read his wife into a book nine years ago, which would sound pretty crazy if you weren't able to see proof of it for yourself. Of course, Meggie's mom and Mo are both book-crazy, so maybe that counts for something.
"Wasn't it kind of me to reunite you with your little girl last night? At first I meant for it to be a surprise for you today, but then I thought: Capricorn, you really owe that child something for bringing you what you've wanted so long, and of her own free will too." (17.41)
Capricorn's saying something that sounds very nice and family-oriented, but obviously he has an agenda, and now that he has Meggie, he knows Mo will do anything he asks in order to keep his daughter from being harmed. This is one of the downsides of having a family, since attachments make you easier to manipulate and coerce.
"Do you see those names?" he asked, pointing up at the chiseled letters listing people no longer alive. "There's a family behind every name—a mother or father, brothers and sisters, perhaps a wife. If one of them were to find out that letters can be brought to life, that someone who's only a name now could become flesh and blood again, don't you think he or she would do anything, anything at all, to make it happen?" (27.4)
Mo makes a good point: Family bonds are strong, and not even death can break them. This also makes us realize that even though nine years have passed since Meggie's mom disappeared, Mo hasn't given up hope of finding her again. There must be something in the way he can magically read people out of books that'll help him find out where she is and bring her back.
With a satisfied smile, Capricorn puts his hands in his pants pockets. "Yes, you all love something, softhearted as you are," he said. "Children, grandchildren, brothers and sisters, parents, dogs, cats, canary birds […] There are no exceptions: farmers, shopkeepers, even policemen have families or at least keep a dog." (34.50)
If you broaden the definition of family to include pets, as well as really close people who aren't necessarily biologically connected to you, then yes, Capricorn's statement is true. Everyone has something or something that they love. Family is just a convenient name for the category of people whom you'd do anything to protect.
As for Elinor, she didn't know whether to laugh or cry. She would have rather seen her favorite niece again anywhere but here. (50.50)
That's one of the annoying things about family; they're always popping up where you least expect them. Like in prison cells, jeez. Elinor is bummed to see Resa/Teresa, her niece, in Capricorn's prison—as far as Elinor knew, she was still inside Inkheart, but now she's not only back in our world, she's also in deep trouble. Bummer.
"Wait!" spat Basta. "Stop, stop, not so fast. Where are you off to, then, Resa? To join your beloved family? You think I didn't understand all that whispering down in the crypt? Well, I did." (57.25)
D'oh. It was better when Capricorn and Basta didn't know who Resa was, because then they'd only have another way of coercing Mo and/or Meggie into reading for them. Now Capricorn's dead, but Basta is still pretty good at threatening people into getting his way. And when you've got a family member there to threaten, well, so much the better. Luckily Basta lets Resa go in order to distract everyone so he can escape. Whew.
Meggie stayed in the big house with her mother. They would sit together at a window looking out at the garden where the fairies were building themselves nests, gently glowing globes that hung among the branches of the trees. (59.22)
After Meggie's mom has been gone for so long, it makes sense that they'd want some mother-daughter bonding time, so while Mo is helping Elinor restock her library, Meggie and her mom sit together. They can't talk, because Teresa lost her voice coming out of Inkheart, but she writes and writes and writes some more in order to fill her daughter in on everything that's happened in the last nine years. This sounds like a nice—if quiet—family reunion.