Pintsized Powerhouse: Laura was small even by the standards of her day, when people in general were shorter than they are now (she was barely five feet tall as an adult). Despite this, she's strong enough to rip the bolts out of a bench that had been fastened to the floor of her schoolhouse. She has no problem helping bring in the harvest or assisting Pa with construction on their various homes. On several occasions he calls her "strong as a little French horse."
Laura's husband and the main character of Farmer Boy
Amazon Chaser: You get the impression that he likes Laura for her spirited temper (it seems to amuse him), and he's very indulgent of her more tomboyish tendencies. While Pa never let Laura ride or drive his horses because she might get hurt, Almanzo lets her drive all of his horses and buys her a pony just for fun. He's also respectful when she tells him she doesn't want to promise to obey him as part of their marriage vows, telling her that he'd never expect her to take the vow seriously even if she did say it, but agreeing to ask the preacher to leave it out anyway.
Cool Horse: It's his horses, a pair of matched Morgans named Prince and Lady, that first catch Laura's attention. At a Fourth of July celebration in Little Town on the Prairie, he enters them in a buggy race despite not having a buggy and having to make do with a much heavier cart than any of the other competitors are driving... and wins.
Dogged Nice Guy: Drives forty miles in a blizzard to bring Laura home for the weekend. After she's said she's not interested in him.
The Determinator: Undertakes a perilous journey through the snow in order to find grain for the town.
That's nothing. He continues to maintain both of his farms despite debilitating illness and suffers a stroke for it. And it still doesn't stop him from trying, even though he was historically dependent on a cane the rest of his life (which is never mentioned in the Rose books).
Embarrassing First Name: He explains to Laura that it's a Wilder family tradition, derived from the name of a Moor ("Al-Manzoor" or something to that effect) who saved the life of one of his ancestors.
Laura's little sister, known as "Baby Carrie" up until Plum Creek or so. She's too young to be Laura's playmate, but she later comes to look up to and admire Laura, while Laura appreciates her company and matter-of-fact sense.
Shrinking Violet: While Laura and Mary are both rather shy, they hide it better than Carrie does.
Laura's baby sister. Grace was only eight or so when Laura married and left home, so she never featured heavily in the books. Rose describes her as 'jolly' in On the Way Home, and when she isn't acting rather spoiled, she is a lot like Laura.
Generation Xerox: Like Laura, she was rambunctious, prone to singing, temporarily a schoolteacher, and married a farmer.
Tagalong Kid: She wants to be, until her parents put their feet down.
Spoiled Brat: Owing mainly to the fact that she's about ten years younger than her sisters.
Laura's daughter and main character of the spin off series 'The Rose Years'.
Beware of the Nice Ones: Gentle, ladylike Ma shocks Laura when she remarks with unusual fierceness that Almanzo, who is courting Laura, is likely to get Laura's neck broken driving her around behind half-trained horses and she hopes he breaks his own first. Ouch.
Massive Numbered Siblings: If you can track down a late-'90s/early 2000s printing of the spin-off books, with an unabridged family tree, Charlotte had by far the most siblings of any of the protagonists, though many died young.
Star-Crossed Lovers: With Lew. She's the daughter of a lord, he's the local blacksmith. Historically it is established fact her parents disapproved of the match and probably a major reason they emigrated to America to get married.
Tomboy and Girly Girl: Tomboy to Grisie's girly girl. Martha likes footracing and playing with the village boys. Grisie prefers to stay inside sewing.
Uptown Girl: Again for Lew, as Martha is gentry and he is working class.
The Caretaker: When Laura and Almanzo come down with diphtheria, he's the one who comes out from town to nurse them, figuring that he's single and there's no one he can spread it to.
Those Two Guys: He and Almanzo sometimes come across as such, from Laura's point of view.
We Named the Monkey Jack: Twice. First, Almanzo names a mule "Roy" after him, probably meant to be unflattering. Later, he names a colt "Royal," saying that Royal was the crown prince of his family and that this colt would be so of the Wilders' horses— this was probably meant to be flattering.
Eliza Jane Wilder Thayer
Cool Aunt: To Rose, as she's much more modern and forward thinking than Laura and Almanzo, who are generally content with things as they are. While Rose grew up on her mother's stories of homesteading with her family, E.J. homesteaded as a single woman.
Doting Parent: To her son, Wilder Thayer, and to Rose when she lives with her during high school.