Nod. "I'll be careful."

"Good habit to get into," says Healer Pendleton warmly.  "All right - either of you have any questions for me?"

"I don't..."

Hagrid shakes his head.

"All right!  Chocolate frog?"  He proffers a little pentagonal package.  "They're not really frogs, they just jump.  They come with famous wizard cards, some wizard kids like to collect them."

Cool!

She goes ahead and eats it, pocketing the card.

"Thank you!"

Hagrid and Healer Pendleton both smile fondly at her excitement.

With their business at St. Mungo's concluded, Hagrid takes her back through the Floo to the Leaky Cauldron - then, out the back door of the Leaky Cauldron, which leads to a sad little brick-walled courtyard.

Hagrid squints at the bricks in the wall, the one opposite the backdoor.  He takes out his flowery pink umbrella and taps sharply on five bricks in sequence, that look to Harriet's eyes exactly like all the other bricks in the wall.

A change comes over the wall, somehow - and then the bricks start moving, rotating and sliding and slotting around each other, reconfiguring the blank solid wall into an archway that leads to -

Well, Diagon Alley, presumably.

St. Mungo's had been strange enough; Diagon Alley is something else.  The place is abustle with palpable wizards, in swishing robes or multicolored tuxedos, pointed wizard caps or glossy top hats, pinstripe suits that turn into cloaks below the waist; with luggage that floats on strings above them like helium balloons, or suitcases that levitate behind them or scuttle on nine legs, or knapsacks that flop along the ground like beached octopuses.  The road itself is only wide as a narrow muggle road, but with no cars to speak of it feels quite a lot wider, clusters of people flowing around each other easily each way.  Occasionally someone will float by lazily on a broomstick, feather-light trunk bobbing in the breeze behind them.

Hagrid leads her through the bustle, occasionally nodding or waving politely to somebody as they pass.  The storefronts are eye-catchingly strange.  Not just for what they advertise, though that would certainly be enough - owls and broomsticks and wizard's robes, chocolate frogs and improbably tall ice cream sundaes, mandrake hearts and dragon livers, and the first books she's ever seen that live up to words like "tome" and "grimoire". But the signs advertising those things were themselves clearly magical.  Some of them glow!  Some of them flash different colors.  Some of them have little people painted on them, cheerfully ushering dancing letters around to form slogans and advertisements.  Some of the windows look in on interiors clearly too large for the buildings that contain them, producing an odd visual effect as she walks by.

Finally, they reach a tall, grand white building, towering over the courtyard in front of it and the stores huddled beside it, that Hagrid identifies to her as Gringott's Wizarding Bank.

This is all so amazing!!! Harriet's mostly speechless, staring at each and every thing, though when they get to Gringott's she asks, "How does a magic bank work?"

"Gringott's is run by goblins," Hagrid says.  "Goblins have magic that lets them work metal in ways that wizards can't, so they mint wizarding money that wizard criminals can't counterfeit.  Folk mine alchemical-quality metal, or buy it from muggles, and bring it to Gringott's to be minted into alchemical gold, and then spend it as money.  And Gringott's has vaults, miles underground, where they let you keep your gold that you're not carrying around, or anything else you want to keep safe."

"Cool!!! What're goblins?"

"Goblins're a type of magical person.  You'll see plenty of 'em inside.  Don't always like wizards much.  Wizards... haven't done right by 'em."

"Huh. Why not?"

Hagrid sighs sadly.  "Some wizards think they're better than people who aren't wizards.  Some... act like it even if they don't think it, or don't do anything about the ones who do."

"Oh."

"They shouldn't do that..."

"Lotta things folk do that they shouldn't," Hagrid says solemnly.

Slow nod.

Into Gringott's.  Through a towering pair of bronze double doors, and then another set of silver, and they're in a vast warmly-lit room flanked on either side by long counters, behind which are seated, presumably, goblins.  None more than three feet tall, with wrinkled faces and solidly black eyes and long pointed ears, talking gruffly to wizard patrons or examining gold and jewels.

Hagrid proceeds to a free teller.

She tries really hard not to stare too rudely.

"Mornin'," Hagrid says briskly.  "This is Harriet Evans, heir to the Evans-Potter vault.  We only just found her - "

"We received Albus Dumbledore's owl on the subject," the goblin says.  He hands over a small golden key.  "Have her test this."

He nods, and turns to Harriet.  "This is yer vault key," he says.  "Hold it up where he can see it - it'll light right up, and that'll show you're James and Lily's daughter."

She bites her lip and takes it, holding it up.

Little curling patterns of white light spread up the body of the key from where she touches it.  The goblin watches, and nods smartly.

"Miss - Evans?" he says, and leans forward.  "What are your guardianship arrangements?"