Reconsider your position

A moment of reconsideration is in place. You begin to realize that this quest of vengeance is misguided at best. At this size controlling your movement is precarious, and you might actually destroy the entire building, which you certainly don't want. The military would be onto you so fast, and not even mile-tall giantesses could tank nukes.

Yes, you believe that this calls for an entirely different approach. You march onwards to downtown where the GWR office is located. The awestruck gaze of onlookers feels as if it could burn a hole through your clothes. Beaming with smug confidence over your gargantuan, impossible stature, you decide to feed the fire and discard your attire down to your underwear.

There's something engrossing about the way your mere existence causes a scene. Cars skid off roads and pedestrians run for cover. Panic soon turns to captivation as people realize that your elegant gait rattles windows, but doesn't leave even the faintest of dents into the concrete. Even the most cowardly of civilians soon peek back in curious bewilderment after you've passed.

Who is this colossal woman? How did she become this way? They all yearn for knowledge on what she is and more importantly, what she's going to do. You savour this attention, keeping the public on the very tips of their toes as you close down on your target.

Jude McKinely has just elected to spend the lazy morning on a coffee break. She cusses the caffeine-greedy GWR interns in her mind upon finding the coffee pot empty. After filling it up and setting the percolator down, she notices faint ripples on the water surface.

Jude: "Are they doing construction work? Would've expected them to give notice or somethin'."

Without being given further time for incorrect assumptions, Jude is interrupted by one of those ill-spoken interns who frantically bursts into the room screaming:

Intern: "GIANTESS! A FUKKEN' GIANTESS IS OUT THERE!"

Indeed, as Jude runs to open the blinds of the dim room, she's greeted by a very literal wall of abs from her third floor window. The nature of her situation takes a while to set in.

Jude: "..."

You: "Jude! Ju-uuuu-de! I know you're in there, come out come out wherever you are!"

Her face pale as paper, Jude runs out of the break room and out into the open office arrangement. You crouch down and peek through the large windows inside. You don't of course know what Jude looks like, but the fleeing madwoman's appearance is precisely what you'd expect based on having heard her voice.

Sophie: "I know you're in there! C'mon out now you silly goose, I'm not gonna eat you, promise!"

Jude isn't coming out. How about that. She locks herself in a restroom.

Sophie: "Rude. Let's see how far that gets her."

Jude only gets a second to compose herself in the bathroom, before another quake rocks the building - this one a gargantuan. Outside, you've hoisted the entire building from its foundations and are carrying it one-handed. Surprisingly, there appears to be hardly any damage to the five-story building at all despite its asymmentrical shape, a lack of support and proportionally frail construction. There's probably some size-related magic fudgery going on that you don't dare to bother your head with.

You shake the building in your hands a bit. As per the just-established altered physics, all loose items are thrown and scattered around the place, but nothing seems to break or sustain damage.

Sophie: "Show yourself Jude, you don't want to turn down potential record-breakers, do you?"

The GWR correspondant shakes in fear at the surreal situation. The entire building should be rubble and rebar by now, but the fluorescent ceiling lights are still on and the bathroom mirror is tumbling around the WC harmlessly, without a crack.

Jude: "(Oh god oh god the fuck is going on...? T-this can't be happening...)"

Suddenly, a jerking motion somehow dislodges the bathroom lock and sends Jude flying through the air. A few consecutive tilts, and she helplessly tumbles out of the front door like a marble from a handheld maze. She falls at least thirty feet directly onto concrete, painlessly and sustaining no injuries whatsoever. She groggily looks around, expecting to find herself in the afterlife, but only seeing your oddly distant face.

Jude: "Buhh..."

Sophie: "Wakey wakey chicken dinner!"

You slam the GWR building back onto its original plot. It still sustains no damage, and in fact the gutters are cleaned out and the flaky, worn-out paint peels right off revealing a stylin' brick exterior.

Sophie: "So then. How's about those measurements?"

Jude: "... You know what, fine. Igf- if you really wanna, we can give you official m-measurements."

Sophie: "Yay!"

Jude: *cough cough* "But just so you know, breaking an existing record costs a thousand dollars."

You have a double take.

Sophie: "...What?"

Jude: "Eh, we gotta make money somehow."

Eff that, you don't have a thousand dollars. Once word really gets out about your existence, you'll probably garner enough public outcry to **** GWR to recognize you anyways.

Now you're a giantess, and apparently incapable of causing inadvertant damage to anything.