She is simply not ready, for underwear.
Nor does she have 100% fully developed impulse control, with her body.
She is still at the naked on the bottom stage.
She is still not a rocket scientist about it.
Don't rush it.
And certainly, she is not at the stage of going out, with underwear.
These things comes in stages. Per the physiological cues, and development, of the child.
My son was like that.
Only he began the process at 3. On his own. Naked at the bottom. At home. Then one day, he was ready for underwear. At home. We took it in stages. Then one day he was ready for going out, with underwear, versus with a diaper. And we'd take SHORT outings. And it all occurred without battles.
It all goes in stages. Per the child's physiological ability and organ development.
First is: getting competence about it at home. Then, getting ability over their bladder outside the home.
Then, night time dryness is a whole other stage. Night time dryness is not the same as daytime pottying. Night time dryness, is something that occurs, physiologically, even until 7 years old.
And.... you have only been doing it for the past 2 weeks or so.
That is NOT, long.
Not long at all.