You had a lot of responses to this, and i am late in my response, but I decided to write anyways. My daughter only stopped peeing in her bed at night this year. She was 6 when she stopped. Both her dad and I also wet the bed until we were about 5 or 6, so genetics was working against her. One thing that really helped us control the issue was:
1. Having her go to the bathroom right before bed.
2. Waking her up to go to the bathroom between 10pm - 11pm every night.
Whenever my daughter had an accident, most of the time it was before midnight. That did not change regardless of how we tried to regulate liquids. She is such a heavy sleeper she could not wake up to go. We often found her sound asleep while laying wet in her sheets. So she wore pull-ups at night, and we just lether do whatever. For a while, when she was 5, we tried for a while to let her have accidents and kept putting her in underwear, but after a while we got tired of changing the sheets. She couldn't make it all night, so we went back to pull-ups. Then after a few months we started taking her to the bathroom every night before we went to sleep (around 11pm). We started noticing dry pull-ups in the morning. We stuck with that routine for about a year. In the last couple of months we went back to underwear. If we forgot to take her potty before 11pm, there was usualy an accident, but if we remembered her bed stayed dry. Then finally, we noticed that if we forgot, it was ok. She either was waking up to go, or holding it all night. So after a while we stopped taking her, and she has been dry ever since.
We personally believe that it was her maturing and developing, as well as a very well established routine of night time potty that got things right.
Good luck to you!