No that does not work. Nausicaa now knows a lot of bad words and she is tempted to use all of them. 

"We'll step outside and call him then," and then they can mysteriously vanish. Being shoggoths around humans is dangerous since humans sometimes kill or trap or enslave shoggoths but so is being weird because being weird gets you caught, mom's told her that lots, but running away is maybe less dangerous than being weird here, and maybe they can find an ocean and some Deep Ones or other shoggoths. 

Maybe she should've asked weird magic fox for more powers but weird magic fox might get mad at her if she summons him again.

"Kiddo?" calls the cashier as they go. "Kiddo how are you going to call him without an -"

They slip out of sight, Anna listens to Bright's explanation, and then she can be a denser-than-normal non-reflective low to the ground mass of tentacles with a smaller please-for-once-not-orange-Bright-seriously blob on her back. Running north! And hopefully not being spotted. She tries to keep hills between them and any possible people. (She's also distributing her weight so the tracks she's leaving are only slightly weird and not super obvious to people not experienced in following tracks.)

They are a very good dark blue blob!

Nobody notices them.

The train goes underground after a bit, when the hills get steeper.

There are many farms.

Then there's a town.

She splits from the train tracks there. She has a good sense of north; how else should she navigate in the lightless depths of her homeland?

Bright's fallen asleep, as children do. Anna slows down, and shrinks gently enough she can fold the little blob of tentacles into her arms, and settles into somewhere where she and Bright won't immediately be spotted.

They're going to have to figure out how to steal, beg, or work, and - 

She would've heard, if anywhere known to humans had this kind of technology. Hidden cities exist, but not hidden cities with massive amounts of farmland...

Would they know shoggoths, to hate them? It's a tempting thought, that she could just come forward, present herself as a lost ambassador... Her mother was as close to nobility - or at least fame - as her people have, after all, even if Anna is more inclined to folding herself into her research.

But the shoggoths have rarely had any positive-sum interactions. Certainly not with surface-dwellers, for all that Anna loved a human.

This town possibly isn't big enough for true anonymity though... But it should be enough for them to get a sense of the culture's dynamics.

It's currently a sleepy little town. Peeping in the windows reveals that some people have not purple hair but orange or grey or yellow.

'Sleepy' isn't very promising.

After resting for thirty minutes, she'll circle around and keep moving.

There's a larger city after a bit more travel! This one is lit up and there are people around, purple and grey and a few folks with red hair in trucks.

Purple's been working for them so far.

She'll wake Bright up enough to nudge the kid back into purple-haired-girl (luckily Bright's old and apparently prodigious enough to stay in the shape the kid falls asleep in), and start walking around like she knows where she's going.

Mostly she's trying to observe how they interact with each other. Are there any marked categories - people others are avoiding, or mistreating, or looking away from, or glaring at... Are they friendly to random people, or are they dismissive. What sorts of in groups and out groups do they have...

Also where do they keep their money. Very important, that, if she wants to take pick-pocketing back up. (Hey, it's a useful skill if you spend a significant amount of your time wandering out of the ocean to trek through random human cities.)

People are mostly hanging out with their own colors. Nobody talks to or acknowledges the reds except for one purple having a one-sided shouting argument with a couple of them in a garbage truck. A grey stops a purple and the purple is apologetic and goes on her way without further incident.

Nobody's carrying cash.

So she and Bright won't have red hair and since she doesn't know how 'orange' counts she might need to have a serious conversation with her child about that child's favorite color, and - the greys are peace keepers? Socially respected? Police? Mediators? She doesn't know enough to say which. 

She can eat random biomass technically, if she feels like going back out into nature, but grass will probably give Bright a stomach-ache, and children need actual calories...

She finds somewhere out of the way to chew on her lower lip and fret, and then - do they have beggars? (The mere thought stings her pride, but... She needs to feed her child, and she's still not sure she wants to risk revealing herself.)

There aren't a lot of obvious beggars around in the middle of the night but there is a purple-haired person sleeping on a park bench.

Then she'll look for opportunities to steal food surreptitiously, while waiting for the morning.

A shapeshifter could reach past the grate protecting this storefront and pull out produce small enough to fit through the bars. There's an all-night sandwich shop over there, sparsely patronized.

The sandwich shop still has people.

She'll try leaning against the wall nearish the grate on the first storefront, and snaking a tentacle in to grab whatever's small enough. A good pile of it, she'll have a harder time stealing in the daylight. (If she was as good at shapeshifting as her mother she could've just squeezed into the storefront to look around... That might be something for Bright to do, tomorrow night, if the kid's awake.)

She gets a haul of nuts, berries, and little green vegetables. Nobody notices.

Sorry kid, you're having vegetables for breakfast. 

She'll form a backpack and put her haul in it, eating some of the berries for herself since they won't keep well, and keeps wandering, repeating the trick with any other similarly locked down storefronts she sees. 

There's nothing else produce-like but there is a convenience store with snackfood she can reach like that.

Maybe that'll make Bright happy. 

Once she has a backpack and a stomach full of produce and snacks she leaves off.

Can she steal anything containing water or other drinks, too? Bright's going to get thirsty pretty quick, especially if the kid can't swim anywhere.

The convenience store display has bottled water and soda and juice both sparkling and non-, though she doesn't have that much time to raid it before someone comes around the corner.

She mostly steals non-sparkling water and juice, and she'll look down and close in her body language when the person walks around the corner.

(Hopefully that someone doesn't spot the tentacle merging back into her body from the start of another theft.)

The person blinks but doesn't say anything and walks right by.

She'll steal a few more things of juice and then walk off.

The town starts waking up around sunrise; people emerge from subway stations to walk the rest of the way to work and they open up stores and restaurants and schools and offices.