E. Nesbit

Edith Nesbit (1858-1924) was a popular and influential English author of children's adventure stories. Her married name was Edith Bland (née Nesbit).

Famous works include The Story of the Treasure Seekers (and sequels), Five Children and It (and sequels), and The Railway Children.

E. Nesbit was unusual for her time in writing children's stories set in the real world, instead of in a made-up fantasyland, although many of them (such as Five Children and It) contain fantasy elements.

Works by E. Nesbit with their own trope page include:

Five Children and It (and sequels)
The Railway Children

E. Nesbit provides examples of the following tropes:

The All-Concealing "I": Attempted by the narrator of The Story of the Treasure Seekers, not very effectively; the narrator is a child and is only concealing their identity as a game for the reader.
Call a Pegasus a Hippogriff: Trope Namer. In "The Book Of Beasts", the hero must summon a creature identified as a hippogriff to save his city from a dragon. The creature that appears is what most people would identify as a pegasus, a winged horse. To be fair, you can't say that a hippogriff isn't a winged horse (or that a pegasus isn't technically part horse, part bird for that matter). It's also possible that Nesbit figured that the word pegasus must only refer to the Pegasus.
Curious as a Monkey: The protagonist of "The Caves and the Cockatrice":

His inquiring mind led him to take clocks to pieces to see what made them go, to take locks off doors to see what made them stick. It was Edmund who cut open the India rubber ball to see what made it bounce, and he never did see, any more than you did when you tried the same experiment.

Genre Savvy: "Melisande" is set in a fairy tale world where everyone is Genre Savvy. For example, the king and queen deliberately refuse to hold a christening party, knowing what happened to the Sleeping Beauty. When all the fairies are furious that they weren't invited, and they want to curse the princess, the king points out that traditionally, only one of them can curse the princess or they'll go out "like a candle-flame". He's more or less bluffing, but since the evil fairy Malevola already did the cursing, they decide not to risk it, thank the queen for a lovely afternoon, and leave.
It Was Here, I Swear: The end of "The Caves and the Cockatrice"
Magic Pants: Lampshaded in "Melisande"; when fairy magic causes the princess to grow to enormous size, it's mentioned that things could have been quite inconvenient if her clothes hadn't grown with her.
Moustache De Plume, ambiguous initials subtype
Narrator All Along: Played for Laughs in The Story of the Treasure Seekers. The narrator keeps praising one of the main characters as being so clever and brave, and how it isn't his fault when things go wrong. Then the narrator begins forgetting to use the grammatical third person...
Nurse with Good Intentions: In The Story of the Treasure Seekers, the kids decide they want to invent medicine. So they try goofing around in the cold until one of them gets sick. Eventually, one of them does and they try to give him all sorts of medicines...but none work and he just gets worse. Needless to say, the adult who discovers this mess is not amused.
Our Dragons Are Different: "The Dragon Tamers" includes a Western style dragon covered nose to tail in rusty armor plating; after a set of adventures (including a fight with a giant), he ends up befriending the blacksmith's son and the other children in the village, after which the armor falls off and the dragon turns out to be the world's first cat.
Rapunzel Hair: In the comedic fairy-tale story "Melisande", Princess Melisande is cursed at birth to be bald. When she grows up she is given a magical wish, and at the prompting of her mother requests long, lovely, fast-growing hair. Hilarity Ensues.
Relative Error
Unreliable Narrator: The narrator of The Story of the Treasure Seekers and its sequels.