Leave her in panties. If you switch to training pants or pull up pants, she doesn't get the trickle of pee running down her leg to remind her to run and you won't be able to see that she's had an accident because the training pants/pull ups absorb that, so there's no visual clue she's wet for you.

I would have set times where you send her if she's not been lately. i.e just before you go outside, expect all children to pee or at least go and try, same for lunchtime or whenever. That way, she's not singled out but where she's resistant, it's not an option but to go and try.

If she's newly toilet trained and everything you say suggests that's true, just tell her (not ask her) to go if she's not been in there for a while.