Eagle-eyed viewers of the videos will spot that she only has one back leg. ... Now the leg isn't bothering her she's much happier, as you can tell, and is now a very spoilt housecat.
Despite having watched both videos, with some amusement, I hadn't noticed that.
... which is probably a good sign. Well done on taking her on, not an obvious choice for many people.
I've met three legged cats, even outdoors, so I suspect they are quite capable of being able to live a life as indoors/outdoors cats. I wouldn't necessarily deprive her of outdoor access, although you may have to think a bit about giving her ways to escape other cats, although that's potentially an issue with any cat. I'm guessing at her age, she hasn't been spayed and/or fully vaccinated yet, so isn't going to be let outdoors yet anyway.
She does looks to be happy, and like all kittens, somewhat insane.