Seconding Fate, the rules do a good job of supporting the fiction rather than encumbering it. I felt it very much supported that feeling of “I can do anything I can reasonably imagine.”

To help with the tyranny of the blank page, I’d recommend coming up with a pregenerated character to demo how it all works. Then, encourage her to change or adjust anything she wants to on the sheet. My players initially found it easier to modify something to their liking than to come up with something from scratch.

Magic can be as simple as “Roll your Lore skill” if you want or you can look up several more detailed add-ons that are out there, like Fate High Fantasy magic.

The rules are freely available here: https://fate-srd.com/fate-condensed.

Man, we ended up setting up a wiki for all the ones from my last campaign… it’s down at the moment, but here are a few I have saved on my phone:

“My companions and I are professional adventurers”

“Some of us more professional than others…”

“For no sexy reason, what does the pope look like?”

“Also, I’m not doing terrible! But I definitely just got stabbed.”

Bard: “No, this is wholesome [Bard] moment! Anyway, how much money do you have?”

Sorcerer: “[Ranger], we are about to do some wacky-ass magic”

Ranger: “In that case, I would like to watch it from over there.”

Sorcerer: “I will not be doing it. I will be joining you.”

GM: “Divine and wild magic start pouring into and it’s like… Have you ever licked a battery?”

GM: “Divine, chaos, and dragon magic flows through you—”

Bard: “And bardic from the inspiration!”

Ranger: “Oh I can add some ranger nature!”

Sorcerer: “And I have one that can help! I cast minor illusion to make a “do not disturb” sign.”

“If I take one more step, it’ll be the furthest I’ve ever been from home…”

“You didn’t even have to step.”

“If I take one more interdimensional vortex…”

“Your left or my left? You’re an orb.”

“I am.”

“Float like a flowerpot, sting like a school bus.”

Ahhh, loads of them!

D&D adjacent stuff like Pathfinder 2e.

PBTA and kin like Dungeon World, Monster of the Week, Ironsworn. Blades in the Dark.

Delta Green.

I have a whole folder of freeform, GMless stuff like Microscope, Kingdom, Follow, Archipelago, Dawn of Worlds, Dialect, Intrepid, The Quiet Year.

Gonzo one shot stuff like Paranoia, The Sorcerer Supreme, Ten Candles, peace was never an option (think untitled goose game: the rpg).

I recently had a test run or two of Fate Condensed and got completely hooked.

Most of those I’d be content to run or play, but the game I really want to GM myself is a campaign I’ve been dreaming up for about year now that I call the “sedition sandbox”. The scope is focussed to a single city, the capital of a hostile foreign empire. The PCs are an elite team of saboteurs and infiltrators, sent by a nation desperate to turn the tides of a losing war. Their only objective is to bring down the empire from within. Intrigue, plots, rebellions, sabotage, faction politics, assassinations, propaganda, blackmail, anything the players can think of to achieve that goal is fair game. How far will they go to stop the greater evil?

I think it would be a blast (naturally, I guess), and one or two players in my local network have expressed a little interest, but I’ve yet to rally the kind of commitment I think I’d need to really get off the ground. And the inexorable march of time makes it less likely with every passing day, as my friends either move away or are subjected to all life’s little tyrannies of responsibility ¯\_(ツ)_/¯

Seconded! OP, in a similar vein as the world building games you already mentioned, you might find Intrepid interesting. I could see it being used to do world building + history of some of the major players and nations therein.

I could also imagine the relationship map it uses being hacked a bit to allow for some Disco Elysium style personality skills / thought cabinet shenanigans if you were interested in leaning into that in particular.