I talked to my pediatrician about this because I was dealing with the same thing. He said that they don't worry about kids still being in pull-ups at night until they're older, around 7. I've also heard that kids are usually not ready to be without pull-ups at night until they can wake up for a month without being wet.
My daughter was starting to wake up dry more and more when I decided to push it. She was 5. First, I cut out all drinks for a few hours before bed. I'd also still wake her up to go before I went to bed. If dh or I woke up in the middle of the night, we'd get her up. We didnt' do it all the time though.
She didn't have too many accidents so she must have been ready. To help with the accidents, a friend did this. She put down a mattress cover, then a sheet, another mattress cover, and a sheet. So if her child had an accident, she would quickly remove the top sheet and mattress cover and her bed was ready again. Of course she'd also have to change her.
I don't think it's a matter of effort on your daughter. I think kids at this age sleep soooooo hard that it just doesn't wake them up. My dd just turned 7 and she never has accidents. But, there's an occasional night where she'll go just a little bit and she quickly wakes up and runs to the bathroom. When she was 4 1/2, she would completely sleep through it all and didn't know until she woke up the next morning.
Well, she has had accidents when she was sick. If I gave her something with antihistamine in it, it would make her sleep harder and she had a few accidents.
L.