C.K.
She's just not ready yet.
With my first child, I had my son on a schedule of going on the potty every 20-30 minutes (depending on how much he'd had to drink). This started when he was around 2 years old.
He was 100% out of diapers by 3.5 years. (We had two incidents with diarrhea that scared him to go #2 and that set us back, but over time we overcame that).
My daughter, now almost 2.5, started using the potty at 18 months because she saw her brother. Other than when she sleeps, she is 100% potty-trained.
I had no agenda or time set for getting them potty-trained, it will happen when it happens. As a former teacher, I can attest that all children are potty-trained by the time they go to Kindergarten.
Don't be disappointed at her set-backs (although it's very frustrating!), just keep trying without great expectations.
Good luck, it will happen
c