We're only day trained here but I would just ask her if she had to go. Like every five minutes. And if she kept saying no, I'd just put her on the toilet every 15 minutes. It's exhausting but she finally caught on. It took her maybe 1 week of accidents in her pants and maybe 2 week of her pooping her pants (she was too embarrassed to tell me she had to go) but something in her just clicked.
Now if only she'd stay dry overnight...