Night potty training for 4.5 year old

Alright - 4 and three quarters! She'd want you to know that!She's been day trained for at least a year. Can go hours without peeing during the day.She's been in pull-ups at night for a long time.​She's getting really annoyed with still having to wear pull-ups and would love to just be in her undies. This has been amplified by the fact that her younger cousin has had a couple of sleep overs here and doesn't need pull-ups at night. So now she's really keen.But she's a heavy sleeper. Her pull-up is always full in the morning, and often quite a lot, so either it's two wees or a really big one. She doesn't stir at all overnight. She claims she wakes, but we seriously doubt it, because she makes no effort to get up or even make a sound.So...how do we start this? I've read people saying that there are physical changes that need to occur for night training to be successful, and maybe she's just not there yet. Which we would be fine with. But she's not! She's been asking more and more over the last 6 months and we keep saying soon, and we will have to practice etc. But it's wearing thin.We could try getting her up, but that just seems to be missing the point - it's neither A) helping her bladder to hold on all night, nor B) helping her to wake herself *before* she needs to pee. It just seems to be training her to be woken by us just so that she can have dry undies in the morning. Kind of like learning to drive with someone else doing the shifting part of it.Suggestions? via /r/Parenting https://ift.tt/2rfa503