Have you tried lifting her?
What I did with my dd was to lift her late evening.
To start with I would put her in pull ups then wake her about 10pm (ish) for a wee. If she did great, but more often than not the poor love fell asleep on the potty!!! I had to keep trying to keep her awake! I think I started this just before she was 4yo.
Then once she sort of mastered the fact I was going to wake her up, I took off the pull up and put her in pants (she wont sleep with a bare bum!!) with a protector under her sheet.
Naturally we had a few accidents, especially if I was 15 mins late, but once she was dry for more than a fortnight, I gradually increased the time over 5 months to just before I went to bed at 11.30-12am.
Then a few weeks ago, I totally forgot (had a horrendous cold so wasnt feeling 100% ) and she managed to stay dry all night.
I leave the potty in her bedroom, as she is frightened of the dark, even though we leave the bathroom light on, so she can use it if she needs too.
She seems to have reached the stage of being able to wake herself up if she needs a night time wee.
Kids will do it in their own time, but think about this way, as my dd was exactly the same as yours