My daughter was the same way at that age. I ended up not letting her have anything to drink for at least an hour before bedtime, then having her use the bathroom before bed, and also setting my alarm to wake me up at around 2am. Then I would get her up and take her to the bathroom again. This helps to train her to wake up when she needs to go, and gets her to actually walk to the bathroom when she needs to go.
A lot of times, children (and adults) dream of peeing. It's weird, I know, but I had a hard time when I was a kid, I wet the bed until I was 11, so it's difficult. I would dream I was peeing, but I couldn't get myself to wake up to use the bathroom, so I wet the bed. I had to tell myself before I went to sleep, that if I dream of peeing, I had to put in my dream that it would wake me up when I saw a toilet (there was always a toilet in my dream). Anyway, this worked for me. Even now, at 40, I sometimes dream of peeing, and it wakes me up when I see the toilet!
Try those tricks, and make part of your bedtime routine be a chat about visualizing getting up and going to the bathroom. Don't expect miracles to happen overnight. It takes awhile to train your mind and body to get itself up when it is asleep.
Good luck!